Process and system

Abstract

The present invention provides an apparatus configured to operate a process for the atomisation of a molten calciferous material, the apparatus comprising a reservoir for containing a molten calciferous material, the reservoir comprising an outlet to produce at least one molten calciferous stream; and means for directing at least one fluid stream at the molten calciferous stream such that the at least one fluid stream impinges the molten calciferous stream at an angle effective to atomise the molten calciferous stream to produce an atomised particulate material, wherein the outlet is configured to provide the molten calciferous stream as a linear stream, and wherein the means for directing the at least one fluid stream comprises a series of directing means configured to direct multiple pressurised fluid streams to impinge the at least one molten calciferous stream on its opposite sides; and a system and a process for atomising a molten calciferous material.

Description

[0001] PROCESS AND SYSTEM

[0002] TECHNICAL FIELD

[0003] The present invention concerns an apparatus configured to operate a process for the atomisation of a molten calciferous material, a system comprising the apparatus, and processes and products thereof.

[0004] BACKGROUND

[0005] Amidst a global drive to reduce carbon emissions and move towards a circular economy, heavy industries, such as steelmaking and cement production, aim to decarbonise as fast as possible. Concurrently, the demand for products of such industries, such as steel and cement, is expected to increase. Thus, effective methods and strategies for decarbonising such heavy industries are urgently needed.

[0006] According to the World Steel Association, every tonne of steel produced emits on average 1.85 tonnes of CO2, equating overall to about 8% of global CO2 emissions. The transition to net-zero production methods in this highly carbon intensive industry requires large capital investment. Additionally, waste materials, such as steel or copper slags, produced in steel production or smelting, in themselves pose significant environmental challenges, especially given that for every tonne of steel produced, 0.13 tonnes of steel slag is produced as a by-product. Copper slag, from copper smelting processes, poses a significant waste issue as around 4.5 million tons of copper slag is produced each year, but only 15 to 20% of it is being used as of 2015. Since these are both heavily wasted materials, finding ways to use them in different industries would reduce overall waste. To move towards a truly circular economy, methods are required to convert these waste materials to useful products.

[0007] Typically, slag is tapped from furnaces and once it is tapped, the molten slag is allowed to cool and solidify in large masses. The recovery of useful materials from solidified slag mass is extremely difficult and costly due to the requirement for handling large masses of solidified material, and the significant amounts of crushing required to get the material to a suitable size for further processing, such as metal recovery or the conversion into useful materials. Cooled slag has two solid phases: a crystalline phase is formed when slag is cooled slowly, and a glassy phase (amorphous phase) is formed when slag is cooled quickly. During a rapid cooling process, the substances in the molten slag do not have time to form stable crystalline compounds, and the thermal energy that cannot be released is converted into chemical energy stored in the state of glass, thus having potential chemical activity, and making the amorphous material highly reactive. Therefore, rapidly cooled slag has favourable cementitious properties and may be used as a supplementary cementitious material.

[0008] Supplementary cementitious material (SCM) is a material that can be added to concrete mixtures in addition to, or as a partial replacement of, traditional Portland cement or blended cements to improve both fresh and hardened concrete properties. SCMs may be added to alter properties of the overall cement blend, including durability, permeability, pumpability and finishability, mitigating alkali reactivity and the overall hardened properties of concrete through hydraulic or pozzolanic activity (or both).

[0009] Steel or copper slags are known to be used to produce SCMs. Typically, these methods have been limited to the addition of small quantities of slag to cement mixtures, and high throughput processing of slags remains a challenge. Examples of current processes provided in the art are given below:

[0010] CN1486951 describes a steel slag cement produced with limestone, clay, sandstone, and steel slag. The steel slag is used as an additive alongside GGBFS in the production of a cement mix, using a maximum of 17% steel slag.

[0011] KR20110050611 describes an admixture composition for cement to reduce the generation of carbon dioxide. The steel slag is similarly used as an additive alongside GGBFS in the production of a cement mix, using a maximum of 10% steel slag.

[0012] Atomisation is a process for breaking a bulk material in the fluid state down into smaller particles. Methods of atomisation have been used for the purposes of metal recovery or slag granulation. However, it is not known to use the process of atomisation to enhance a process for the production of a SCM, both in terms of throughput and improvements in cementitious properties. Examples of current atomisation processes provided in the art are given below: CN110125422A describes a water-atomized steel powder production process capable of simultaneously atomizing through double nozzles. The production process comprises the steps of smelting, refining, atomizing, drying, and mixing.

[0013] EP3838451B1 describes a production method for water-atomized metal powder whose amorphous proportion and apparent density can be increased by a low-cost high-productivity water atomization process even if the metal powder has iron (Fe) concentration of 82.9 at% or more and 86.0 at% or less.

[0014] WO2016197244 describes a process for upgrading titania-rich slags using gas atomisation of a liquid slag to decrease particle size, and processing post atomisation to produce relevant products.

[0015] DE19632698A1 describes a process for the production of fine grained slag sand by atomising liquid blast furnace slag (or other liquid ironworks slags) at above 1400°C with a gas at above 1 x 10-5 Pa, using an atomiser of the type used for molten metal and non-metal atomisation, to form particles of less than 90 pm in size, which are quenched for vitreous solidification

[0016] US20170362680A1 describes a method for recovering metal values from a molten slag composition includes atomizing the slag with an oxygen-containing gas in a gas atomization apparatus, to produce solid slag granules using oxygen. Also described is an apparatus for recovering metal values from molten slag includes a gas atomization apparatus, a flow control device for controlling the flow of atomizing gas, a control system, and one or more sensors to detect metal values in the slag.

[0017] CN1096328A describes a method of granulating slag, comprising: a water stream flowing parallel to the slag stream, thereby forming a thin layer. The slag layer and the flow of water strike a baffle causing the slag layer to break up into particles which are cooled and vitrified by the water in contact with the water.

[0018] Atomisers, the apparatus used to break a bulk material in the fluid state, such as molten metal for example, into smaller particles are also known in the art. Particularly, water atomisation of molten metals is a well established technique, where a stream of molten metal flows through a nozzle and into the impingement of multiple high pressure water jets. Examples of current atomisers provided in the art are given below:

[0019] EP2636761A1 describes an apparatus for atomizing molten slag and recovering valuable metals, and more particularly to an apparatus for atomizing molten slag and recovering valuable metals, which enables molten slag of a blast furnace or a converter or an electric furnace to be atomized and valuable metals to be recovered.

[0020] CN107586900B describes a method and apparatus for spray granulation of blast furnace melted slag, including a melted slag tank, a melting tank, and a Venturi type internal mixing two-phase flow device, which uses a spray nozzle is connected to a high-temperature flue gas inlet.

[0021] CN202415574U describes a molten slag quenching and dry granulating and sensible heat recovery power generation system, comprising a slag receiving device, a high-pressure waterair atomizing slag quenching and granulating device, a slag slow cooling device, a sensible heat recovery power generation device and an exhaust gas purifying device.

[0022] None of the above noted prior art provides an apparatus or process in which waste material from heavy industries, such as steelmaking and cement production, can be effectively and consistently upcycled into a highly reactive supplementary cementitious material product in a high throughput manner that is both versatile and controllable.

[0023] In the prior art, the architecture of the atomisers typically only involves a single fluid stream, and these systems are often optimised to achieve a specific particle shape, size, and a tight distribution of size, rather than to maximise throughput. Whilst there are some examples of systems for air or gas atomisation, these are unable to achieve a high glass content beyond the surface of the resulting slag particles and are low throughput.

[0024] Thus, new apparatus and processes are needed in the steel and cement industries, to produce highly reactive supplementary cementitious materials from steel slags with a consistent particle size, and in a high throughput manner and which is more energy efficient than apparatus and processes of the art. SUMMARY OF THE INVENTION

[0025] According to a first aspect of the present invention, there is provided an apparatus configured to operate a process for the atomisation of a molten calciferous material, the apparatus comprising: a reservoir for containing a molten calciferous material, the reservoir comprising an outlet to produce at least one molten calciferous stream; and means for directing at least one fluid stream at the molten calciferous stream such that the at least one fluid stream impinges the molten calciferous stream at an angle effective to atomise the molten calciferous stream to produce an atomised particulate material; wherein the outlet is configured to provide the molten calciferous stream as a linear stream; and wherein the means for directing the at least one fluid stream comprises a series of directing means configured to direct multiple pressurised fluid streams to impinge the at least one molten calciferous stream on its opposite sides.

[0026] The use of molten calciferous material (for example, molten slag) has been found to be particularly advantageous, for example compared to solid slag, or re-melted slag, due to the lower requirement of energy for the process, thereby providing a more energy efficient process as the atomisation of the molten material is more easily facilitated.

[0027] Advantageously, the apparatus of the present invention provides a means of generating high-value cementitious product from molten calciferous materials at industrial processing rates, which makes the apparatus suitable for direct integration into metalworks or other industrial facilities.

[0028] According to a second aspect of the present invention, there is provided a system for the large-scale atomisation of a molten calciferous feedstock, comprising a multiplicity of apparatuses according to the first aspect.

[0029] The multiplicity of apparatuses may comprise at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, or at least ten apparatuses according to the first aspect. The multiplicity of apparatuses may comprise between about 1 and 150 apparatuses, between about 1 and 125 apparatuses, or between about 1 and 100 apparatuses according to the first aspect.

[0030] Advantageously, a multiplicity of these 'linear atomisers' placed in series or parallel further increases molten material throughput, enabling the production of greater amounts of atomised material in a consistent manner, whilst enabling a high turnover of waste molten material. Further advantageously, the versatility of the apparatus and system according to the first and second aspects means that the system is easily scalable and can process high volumes of molten material through series and parallel scaling of the apparatus to yield a large-scale system.

[0031] According to a third aspect of the present invention, there is provided a process for atomising a molten calciferous material, the process comprising: providing at least one stream of molten calciferous material from an outlet of a reservoir; and directing at least one fluid stream at the stream of molten calciferous material such that the at least one fluid stream impinges the molten calciferous stream at an angle effective to atomise the molten calciferous stream to produce an atomised particulate material.

[0032] The process of the present invention may be operated on an apparatus or system according to the first or second aspects discussed herein. Therefore, all features relating to the apparatus and / or system of the present invention may apply, where appropriate, to the process.

[0033] According to a fourth aspect of the present invention, there is provided an atomised particulate material, produced by the apparatus or system according to the first or second aspect, or by the process according to the third aspect.

[0034] According to a fifth aspect of the present invention, there is provided the use of an atomised particulate material according to the fourth aspect as a supplementary cementitious material.

[0035] The supplementary cementitious material may be used to produce a blend with cement, which may be used in the production of concrete. The supplementary cementitious material may be used as a complete (or substantially complete) cement replacement in the production of concrete.

[0036] For the avoidance of doubt, all features relating to the first aspect of the present invention may apply, where appropriate, to any of the other aspects of the present invention and vice versa.

[0037] DETAILED DESCRIPTION

[0038] Apparatus According to the invention, there is provided an apparatus configured to operate an atomisation process of a molten calciferous material, the apparatus comprising: a reservoir comprising an outlet, and a means for directing at least one fluid stream.

[0039] Reservoir and Molten Calciferous Stream

[0040] In embodiments of the invention, the reservoir for containing a molten calciferous material comprises an outlet to produce at least one molten calciferous stream, which is provided as a linear stream.

[0041] The "reservoir" is to be understood as a means for holding or storing a molten calciferous material, examples of which may include, but are not limited to, a container, a tank, or any other suitable means in the art. The reservoir may include a singular reservoir, or more than one reservoir.

[0042] The at least one reservoir may further comprise heating means to maintain the molten material at a required temperature.

[0043] The at least one reservoir may also further comprise mixing means, such as a stirrer, for maintaining the molten calciferous material as a homogeneous mixture and / or for mixing any additional dopants that may be added, for example, silica.

[0044] The at least one reservoir may be configured to redistribute the at least one molten calciferous stream, when necessary, to control the throughput of each stream. This arrangement has been found to help regulate flow of the stream and prevent excessive supply to downstream components, for example, the atomiser.

[0045] In addition, or alternatively, the at least one reservoir may be configured to divert any excessive molten calciferous stream(s). This has been found to ensure that the atomiser does not get overloaded and additionally prevents process disruptions.

[0046] The at least one reservoir may further comprise a cleaning means, for example a semi automated frozen slag cleaning mechanism, for obtaining specific throughput and removing any unwanted accumulated residues. The at least one reservoir may further comprise means to prevent and control molten calciferous material splashing, for example, splash plates, means to promote easy cleaning, for example, spray lining mechanisms, and means to prevent the risk of blockage of the molten calciferous material.

[0047] The throughput of each stream may be passively controlled. The flow rate and / or volume of each stream may be balanced and controlled passively. It has been found that this avoids overwhelming the high pressure fluid streams. The passive flow may be controlled, for example, by a combination of overflows and adjustable mechanisms, for example by dam and weir mechanisms.

[0048] In some embodiments there may be more than one reservoir. In said embodiments, the reservoir may be arranged in series or in parallel to one another. Furthermore, in said embodiments the reservoir may contain molten calciferous material from different sources.

[0049] According to the invention, the at least one reservoir comprises an outlet that produces at least one molten calciferous material stream, as a linear stream. Preferably, the outlet is configured to provide the molten calciferous stream as a linear stream.

[0050] The skilled person would understand that by "a linear stream", the molten calciferous material stream may be a continuous stream (or sheet) of molten calciferous material, or a multiplicity of discrete molten calciferous material streams, along a single line or path.

[0051] The outlet may be configured to reshape or split the at least one molten material stream into different flow formations. This arrangement has been found to provide an evenly distributed throughput of the at least one molten material stream, such that optimal slag atomisation can be achieved, for example by maintaining the desired slag head height over the outlet. The outlet may be a nozzle, for example a linear slot nozzle, or a weir or by any other suitable means. The linear slot nozzle provides the molten material in a sheet like form. In the weir embodiment, the molten material overflows over a weir to provide a stream of molten material.

[0052] Accordingly, the at least one linear stream of molten material may be provided as a continuous sheet of molten calciferous material. In alternative embodiments, the at least one linear stream of molten material may be provided as a multiplicity of discrete molten material streams. The multiplicity of discrete molten material streams may be provided as discrete separate streams, or may be in an arrangement such that the discrete molten material streams provide a sheetlike stream. The at least one linear stream of molten calciferous material may take the form of either a single stream, multiple discrete streams, a sheet flow, or multiple sheet flows, along a single line or path.

[0053] In most preferred embodiments, the molten calciferous material linear stream is provided as a sheet flow.

[0054] In embodiments where the molten calciferous material is a sheet flow, the outlet may form a sheet by a linear slot nozzle, from slag overflowing a weir, or by any other suitable means. In these flow shaping systems, the material directly in contact with the molten material may be selected from at least one of graphite, high temperature ceramic (e.g. Alumina or Magnesium oxide), or refractory material.

[0055] Advantageously, by providing the at least one molten material stream as a sheet, the system according to the invention is able to process a much larger input flowrate of molten calciferous feedstock, such as slag, for example at rates of 0.5 tonnes to 5 tonnes per minute. A sheet flow maximises atomisation efficiency by reducing the molten stream diameter, maximising momentum transfer, and penetration of energy into the molten stream.

[0056] A sheet flow presents additional benefits of increased tunability of process conditions to desired output particle size, which makes scaling to high slag throughputs straightforward through increasing the impingement length, or adding parallel streams. Linear scaling also allows for representative testing and optimisation process and product parameters at bench scale prior to a specific industrial deployment. Sheet flows also offer safety advantages as large diameter circular molten streams can easily penetrate atomisation jets without breaking up, which has an increased risk of explosion if combined with subsequent water quenching.

[0057] The molten calciferous stream may be split and / or reshaped into either one or more long sheets of liquid or many smaller streams of molten material. The spreading of the flow into multiple streams allows them to be atomised more efficiently by impinging fluid streams, such as fluid from water jets.

[0058] In embodiments where there are multiple molten calciferous material streams, the streams may be arranged in series or in parallel to one another. The molten calciferous material may be provided at an elevated input flowrate.

[0059] In some embodiments the input flowrate of the molten calciferous material is from about 0 tonnes to about 10 tonnes per minute, about 0 tonnes to about 5 tonnes per minute, about 0.5 tonnes to about 5 tonnes per minute, about 1 tonnes to about 5 tonnes per minute, or about 1 tonnes to about 2 tonnes per minute. In some embodiments the input flowrate of the molten calciferous material is greater than about 0.5 tonnes per minute, greater than about 1 tonne per minute, greater than about 2 tonnes per minute, greater than about 5 tonnes per minute, or greater than about 10 tonnes per minute.

[0060] The throughput of the apparatus may be controlled by controlling the ratio of the molten material flow rate to the fluid flow rate . In particular embodiments of the invention, the ratio of the molten material flow rate to the fluid flow rate may be between about 10:1 and about 1:10, about 10:1 and about 1:1, or between about 5:1 and about 1:1.

[0061] Accordingly, the flow rate per unit length of the linear stream of molten calciferous material is from about 200 L / min to about 1000 L / min, from about 300 L / min to about 1000 L / min, from about 400 L / min to about 1000 L / min, from about 400 L / min to about 800 L / min, or from about 400 L / min to about 600 L / min. Alternatively, the flow rate per unit length of the linear stream of molten calciferous material is greater than about 200 L / min, greater than about 300 L / min, greater than about 400 L / min, greater than about 500 L / min, greater than about 600 L / min, or greater than about 800 L / min.

[0062] Advantageously, the embodiments of the first and second aspects of the invention are able to handle higher input flowrates of molten material than conventional methods in the art, increasing the turnover of the atomisation process. Additionally, it is able to do this at low energy cost per unit slag throughput.

[0063] Fluid Stream

[0064] In embodiments of the invention, there is provided a means for directing at least one fluid stream at the molten calciferous stream such that the at least one fluid stream impinges the molten calciferous stream at an angle effective to atomise the molten calciferous stream to produce atomised particulate material. The skilled person would understand that for the angle of the at least one fluid stream to be effective to impinge the molten calciferous stream, the at least one fluid stream and molten calciferous steam cannot be parallel to one another.

[0065] The at least one fluid stream may be pressurised.

[0066] In particular embodiments, the pressure of the at least one fluid stream may be at least about 5000000 Pa, at least about 6000000 Pa, at least about 8000000 Pa, at least about 10000000 Pa, at least about 15000000 Pa, or at least about 20000000 Pa.

[0067] In particular embodiments, the pressure of the at least one fluid stream may be from about 0 Pa to about 50000000 Pa, about 5000000 Pa to about 50000000 Pa, about 7500000 Pa to about 40000000 Pa, about 10000000 Pa to about 30000000 Pa, about 15000000 Pa to about 25000000 Pa, or about 20000000 Pa to about 25000000 Pa.

[0068] Accordingly, the flow rate per unit length of the fluid stream is from about 200 L / min to about 1000 L / min, from about 300 L / min to about 1000 L / min, from about 400 L / min to about 1000 L / min, from about 400 L / min to about 800 L / min, or from about 400 L / min to about 600 L / min. Alternatively, the flow rate per unit length of the fluid stream is greater than about 200 L / min, greater than about 300 L / min, greater than about 400 L / min, greater than about 500 L / min, greater than about 600 L / min, or greater than about 800 L / min.

[0069] Thus, the at least one fluid stream may be a high velocity fluid stream.

[0070] The throughput of the apparatus may be controlled by controlling the ratio of the molten material flow rate to the fluid flow rate. In particular embodiments of the invention, the ratio of the molten material flow rate to the fluid flow rate may be between about 10:1 and about 1:10, about 10:1 and about 1:1, between about 5:1 and about 1:1, or between about 2:1 and about 1:1. Thus, in embodiments of the invention, the ratio of the molten material flow rate to the fluid flow rate may be about 10:1, about 5:1, about 2:1, or about 1:1.

[0071] The at least one fluid stream may comprise a series of fluid streams. For example, at least 2 fluid streams, at least 3 fluid streams, or at least 4 fluid streams. A person skilled in the art would understand that the at least one fluid stream may comprise a significantly higher number of fluid streams, such as, for example at least about 50 fluid streams, at least about 60 fluid streams, at least about 70 fluid streams, at least about 80 fluid streams, or at least about 90 fluid streams. Therefore, the means for directing at least one fluid stream may comprise a series of means i.e., each fluid stream has its own directing means. In some embodiments, the fluid streams are located solely on one side of the molten calciferous stream.

[0072] Preferably, in embodiments where at least 2 fluid streams are present, there will be fluid streams located on opposite sides of the molten calciferous stream, such that the molten calciferous stream is impinged by the fluid stream from the opposite sides. This arrangement has been found to increase atomisation of the molten material and facilitate the formation of smaller particulates.

[0073] In some embodiments, it is preferable for the apparatus to comprise an even number of fluid streams, for example, 2 fluid streams, 4 fluid streams, or 6 fluid streams. Each fluid stream may have an individual directing means. The fluid streams may be split evenly on each side of the molten calciferous stream. The fluid stream may be juxtaposed with respect to each other on either side of the molten calciferous stream.

[0074] The fluid streams may be symmetrical about a common axis i.e., the molten calciferous stream. This arrangement causes two fluid streams to impinge the molten calciferous stream at a common point, such that a greater degree of atomisation occurs, and higher throughput can be achieved.

[0075] In some embodiments, the apparatus may comprise an uneven number of fluid streams, for example, 3 streams, or 5 streams, or 7 streams. Each fluid stream may have an individual directing means. The fluid streams may be split between each side of the molten calciferous stream.

[0076] The uneven arrangement has been found to increase the degree of atomisation that occurs, and control the amount of throughput occurring.

[0077] In embodiments where there are an uneven number of fluid streams, each fluid stream may impinge the molten calciferous stream at different points. In some embodiments, at least two fluid streams may converge with one another and impinge the molten calciferous stream at a common point. In embodiments where there are at least two fluid streams, each of the least one fluid streams may converge with one another, preferably at a single point or along a single axis. In embodiments where there are two fluid streams that converge with one another, the fluid streams may be referred to as a converging set of, or a converging pair of fluid streams.

[0078] The at least two fluid streams may converge with one another at a single point or along a single axis. The single axis may be the impingement line, meaning the axis where the streams collide with one another.

[0079] In a preferred embodiment, there are at least two fluid streams, wherein the at least two fluid streams converge with one another. The apparatus may comprise at least two fluid streams that impinge one another, interacting with the molten calciferous stream at the point of impingement.

[0080] The at least two fluid streams may converge with one another at a single point or along a single axis. The single point may be the impingement point, meaning where the streams collide with one another. The single axis may be the impingement line, meaning the axis where the streams collide with one another.

[0081] The at least two fluid streams may not converge with another at a single point. The at least two fluid streams may impinge the molten calciferous stream at different points. The point may be referred to as the impingement point, or impingement line.

[0082] The number of impingement points or impingement lines will be dependent on the number of fluid streams present. In some embodiments, there may be at least two impingement points, or at least three impingement points, or at least four impingement points. In some embodiments, there may be at least two impingement lines, or at least three impingement lines, or at least four impingement points. In some embodiments, there may be at least one impingement line and at least one impingement point.

[0083] In embodiments where there are at least two impingement points and / or lines, a first impingement point may comprise the convergence of at least two fluid streams at a single point or along a single axis, and a second impingement point and / or line may comprise the convergence of at least two fluid streams at a single point or along a single axis. In embodiments where there are at least two impingement points and / or lines, a first impingement point may comprise the convergence of at least two fluid streams at a single point or along a single axis, and a second impingement point and / or line may comprise a singular fluid stream along a single point or along a single axis.

[0084] Where the at least two fluid streams are sheet streams, the at least two streams may converge to form an impingement line, where the sheet streams collide with one another.

[0085] The at least two fluid streams may be arranged within a plane, and / or may be angled to prevent interference with one another. Accordingly, the at least two fluid streams may be arranged in a single plane, but the orientation of the fluid streams may vary. For example, the fluid streams may be any of, but not limited to, overlapping, twisted and / or staggered.

[0086] The at least two fluid streams may be provided at different angles.

[0087] The at least two fluid streams may converge with one another, with an acute angle between them of about 10°, about 20°, about 30°, about 40°, about 60°, about 70°, about 80°, about 90°, about 100°, about 110°, about 120°, or about 150°.

[0088] In alternative embodiments, the at least two fluid streams may converge with one another, with an acute angle between them of from about 10° to about 170°, about 20° to about 160°, about 30° to about 150°, about 40° to about 140°, about 50° to about 120°, about 60° to about 100°, about 70° to about 90°, or about 70° to about 80°.

[0089] The at least one fluid stream impinges the molten calciferous stream at an impingement point. The impingement point is to be understood as the point of contact between two streams, i.e., the molten calciferous stream and the fluid stream. The angle between the fluid stream and the molten calciferous stream may be construed as an "impingement angle".

[0090] The fluid stream(s) and the molten calciferous stream may be provided at different angles to one another. The angle between the at least one fluid stream and the molten calciferous stream (the impingement angle) may be between about 10° and 160°, between about 20° and 120°, between 30° and about 80°, between about 40° and 60°.

[0091] The angle between the at least one fluid stream and the molten calciferous stream (the impingement angle) may be less than about 180°, less than about 120°, less than about 80°, less than about 50°. This feature has been found to facilitate the atomisation of the molten calciferous material.

[0092] In embodiments of the invention, means for directing the at least one fluid stream may be a jet. The jet may be any suitable jet in the art, for example the jet may be a fan jet or a solid spray cone jet. The jet may comprise a nozzle. The nozzle may be modified to modify the form of the fluid stream generated by jet, preferably a fan jet.

[0093] The apparatus may comprise at least one jet in a counterflow direction, for example a jet comprising a solid cone spray nozzle. A jet being arranged in a counterflow direction to the at least one fluid stream further atomises any material which may have skipped a first jet. This has been found to improve the atomisation process and further reduce the average particle size of the atomised particulate material.

[0094] The form of the fluid stream depends on the nozzle type. The nozzle may be selected from linear slot nozzles, flat jet nozzles, point jet nozzles or any other suitable nozzle. In preferred embodiments, the nozzle is a flat jet nozzle. Flat jet nozzles have a wide, fan-shaped spray pattern, while point jet nozzles produce a precisely focused spray pattern, and a linear slot nozzle have a sheet spray pattern.

[0095] In preferred embodiments, the at least one fluid stream is generated by a nozzle, which may also be referred to or known as a jet. The nozzle may be a fan nozzle, wherein the fan nozzle creates a sheet of fluid in a fan shape, or it may be any suitable nozzle in the art. The size of the fan generated by the nozzle may be altered by changing the nozzle shape or nozzle hole size.

[0096] In some particular embodiments there may be a multiplicity of converging pairs of fluid streams in series with one another. In such an embodiment, where the fluid nozzles are fan nozzles, the edges of adjacent fans stream produced by the fan nozzles may overlap with one another to create a larger sheet of converging fluid through which the molten material may impinge with. In some embodiments, there may be at least one fluid stream wherein the fluid stream is singular, i.e., is not in a pair and does not converge with another fluid stream. There may be at least one fluid stream that does not converge with another fluid stream, and impinges the molten material at a singular impingement point and / or line. The at least one fluid stream may be in a series with at least one pair of fluid streams.

[0097] When the at least two fluid streams may converge with one another at a single point or along a single axis, the at least two fluid streams impinge the molten stream with the single point or along the single axis. The fluid stream may therefore impinge the molten calciferous stream at a discrete point or along substantially continuously across several points, for example, impinge in a sheetlike formation as a result of a fan nozzle.

[0098] The at least one fluid stream may be a discrete stream, or a sheet stream. Preferably, the at least one fluid stream is a sheet stream. In preferred embodiments there may be a multiplicity of the at least one fluid stream, arranged in series or in parallel to one another.

[0099] According to the invention, the means for directing the at least one fluid stream comprises a series of directing means configured to direct multiple pressurised fluid streams to impinge the at least one molten calciferous stream on its opposite sides.

[0100] The apparatus may comprise at least two means for directing at least one fluid stream i.e., the apparatus comprises at least two fluid streams, wherein the fluid streams converge with one another, preferably at a single point or along a single axis.

[0101] The apparatus may comprise at least two means for directing at least one fluid stream i.e., the apparatus comprises at least two fluid streams, wherein the fluid streams do not converge with one another, and provide two different impingement points and / or lines.

[0102] In alternative embodiments the at least one stream of molten calciferous material is impinged by at least part of the fluid stream generated by the at least one fluid nozzle.

[0103] The fluid stream may be selected from water, oil, or a gas, or any compatible mixture thereof. In preferred embodiments the at least one fluid stream is a water stream. In some embodiments, at least part of the fluid stream may be recycled. The molten calciferous stream may be split and / or reshaped into either one or more long sheets of liquid or many smaller streams of molten material. The spreading of the flow into multiple streams allows them to be atomised more efficiently by impinging fluid streams, such as fluid from water jets. Furthermore, a single set of impinging fan jets is able to atomise multiple melt streams at the same time.

[0104] Advantageously, the result of atomising the slag into particles of a small diameter is that they can cool rapidly, turning into an amorphous solid phase with a high glass content. In this context "small diameter" may be understood to be between about 1 and about 500 pm, between about 100 and about 500 pm, between about 150 and about 500 pm. For example, the small diameter may be understood to be less then about 500 pm.

[0105] The rapid cooling may be achieved by the used of a water bath. The atomised particles may be directed towards a water bath by any suitable means, for example, by high pressure jets.

[0106] The apparatus may further comprise a fluid pumping station to control the flow rate of the fluid stream. For example, the fluid pumping station may supply a jet with pressurised fluid to control the flow rate. The fluid pumping station may comprise a multiplicity of pumps.

[0107] The intensity of the fluid stream is dependent on the pressure of the pump, the flow rate of the pump and the type of the nozzle. Typically, the higher the pressure and flow rate, the more precise the focus of the fluid stream is, and the more powerful the fluid stream.

[0108] The fluid stream is preferably recycled fluid from downstream processes. Therefore, the apparatus may further comprise a fluid recovery system. The fluid recovery system may comprise a flow line to the means for directing at least one fluid stream.

[0109] The apparatus may further comprise a cooling tower and / or filters, for example, for reducing the temperature of water. The apparatus may further comprise water treatment means, to allow reuse of the water.

[0110] Collecting Means The apparatus may further comprise a collecting means to collect the atomised particulate material, optionally wherein the collecting means comprises a solid plate or surface, a water bath, or additional fluid streams (i.e., a jet generating a fluid stream).

[0111] The collecting means may include means for collecting the material (i.e., storage means, solid plate or surface) and / or means for further processing of the collected material (i.e., into a water bath, or into further jets).

[0112] The apparatus may comprise a series of collecting means to collect the atomised particulate material, connected together by transmission means, such as a pump.

[0113] In a particular embodiment where the apparatus comprises a collecting means of a water bath, the water bath may further comprise a series of water baths, such as for example a first water bath and a second water bath, where the series of water baths are connected by a pumping means effective to transfer the atomised particulate material from one water bath to the next.

[0114] Advantageously, such a configuration enables rapid cooling in the first water bath, prior to the atomised particulate material being transferred to a second water bath for further cooling. Such a system achieves the required cooling rates for amorphous content generation post-atomisation for slags.

[0115] In such embodiments, successive water baths may be remote from the apparatus configured to operate a process for the atomisation of a molten calciferous material.

[0116] The atomised particulate material may be cooled prior to collection by the collecting means or by the collecting means.

[0117] The cooling is preferably rapid cooling. Rapid cooling of the atomised particulate material has been found to produce particles with a high fraction of amorphous phases. Therefore, if the atomised particulate material is mixed with other materials, for example cementitious materials, the increased amorphous content has been found to rapidly react and increase the resultant strength of the material. The collecting means may be at least one collection tank, where the atomised product may be collected. The particulate material may be allowed to cool in the collection tank. The at least one collection tank may further comprise sieves to sort the particulate matter by size. The collection tank may introduce additional cooling water to enhance the cooling of the atomised slag. In particular embodiments the collection tank may be a solid plate / surface or a water bath.

[0118] In some embodiments there may be more than one collecting means, for example at least two, at least three, at least four or at least five collecting means. Typically, the collecting means are located directly beneath the at least one fluid streams, such that they collect the atomised particulate matter as it leaves the fluid stream.

[0119] In embodiments where there are more than one collecting means, the collecting means may be arranged in series with one another, with the first collecting means located directly beneath the at least one fluid streams, such that the atomised particulate matter is collected as it leaves the fluid stream in the first collecting means. The subsequent collecting means may be connected to the first collecting means by means of a transmission means, such as a pump and tube system.

[0120] The collecting means may have suitable movement means to move the atomised material, for example, via the use of screw classifiers in combination with conveyers.

[0121] In embodiments where the collecting means includes means for further processing of the collected material, this may include additional fluid streams, preferably sets of additional fluid stream jets.

[0122] In some embodiments, the additional fluid streams may be asymmetric. In other embodiments, the additional fluid streams may be symmetric.

[0123] In some embodiments, the atomised material may be passed through further at least one additional fluid streams and subsequently collected by a collecting means.

[0124] Preferably sets of additional fluid stream jets comprising at least one impinging additional fluid stream, or at least two impinging additional fluid streams are provided. Preferably, when additional sets of fluid streams are provided, they are also impinging. In such embodiments, there may be at least one set of additional fluid streams, or at least two sets of additional fluid streams. The additional fluid stream jets may be provided in pairs and converge at a same impingement point. Alternatively, the additional fluid stream jets may be provided singularly, and have a distinct impingement point.

[0125] Advantageously, repeating the process through multiple sets of additional fluid streams generates finer atomised material products, which provides safety and quality control advantages. This is achieved by catching any molten calciferous material that passes through the fluid streams.

[0126] Further Apparatus Features

[0127] The components of the apparatus or system of the first or second aspect directly in contact with the molten material, such as the reservoir and / or the collecting means, may be selected from any suitable material able to withstand high temperatures, which may be selected from at least one of graphite, high temperature ceramic (e.g. Alumina or Magnesium oxide), or refractory material.

[0128] The apparatus may further comprise additional fluid streams for further atomising the particulate matter. For example, the apparatus may comprise more that one impingement point and / or line.

[0129] The apparatus may further comprise a grinding means, such as, but not limited to, a powder grinder for example, suitable for further reducing the size of the particulate matter.

[0130] The apparatus may further comprise a gas extraction system to collect any gases generated by the passage of the at least one molten material stream through the at least one fluid stream, such as, steam for example. Alternatively, the apparatus may comprise a condenser system, or any other suitable condensation means, for isolating and collecting steam generated.

[0131] The apparatus may further comprise a heat recovery system, to collect and store excess heat from the operation of the apparatus. The heat collected by the heat recovery system may be used to generated electricity and / or to dry the atomised material before storage. In some embodiments, the apparatus may comprise a dryer.

[0132] The apparatus may further comprise a flow control system. The flow control system may control the pressure and / or flow rate of the fluid streams, and / or it may control the flow of molten calciferous material. The apparatus may further comprise a monitoring system. The monitoring system may collect data, such as spectroscopic, micrographic, thermal or diffractive data. The data may be used by the flow control system to control the apparatus.

[0133] The monitoring system may consist of one or more sensors selected from the group comprising infrared, light, thermal sensors, and compositional sensors (which can be an X-ray Diffraction (XRD), an X-ray Fluorescence Spectrometer (XRF), Spectral, gas, magnetic). The one or more sensors are located inside and / or upstream and / or downstream of the gas atomization apparatus.

[0134] System

[0135] According the invention, there is provided a system for the large-scale atomisation of a molten calciferous feedstock, comprising a multiplicity of apparatuses according to the first aspect.

[0136] The multiplicity of apparatuses may comprise at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, or at least ten apparatuses according to the first aspect.

[0137] The person skilled in the art would understand that the system may include a much larger number of apparatuses according to the first aspect, enabling a much higher throughput and conversion of molten calciferous feedstock. In such embodiments the multiplicity of apparatuses may comprise at least twenty, at least thirty, at least forty, or at least fifty apparatuses according to the first aspect.

[0138] The person skilled in the art would understand that in a system according to the second aspect, there could be an unlimited number of apparatuses according to the first aspect.

[0139] The multiplicity of apparatuses may be arranged in series or in parallel with one another and / or wherein the multiplicity of apparatuses are modular.

[0140] Advantageously, a multiplicity of these 'linear atomisers' placed in series or parallel further increases molten material throughput, enabling the production of greater amounts of atomised material in a consistent manner, whilst enabling a high turnover of waste molten material. In some embodiments, the apparatus may be linear or modular. In some embodiments, the multiplicity of apparatuses may be modular and / or easily moveable.

[0141] Advantageously, the versatility of the apparatus and system according to the first and second aspects means that the system is easily scalable and can process high volumes of molten material through series and parallel scaling of the apparatus to yield a large-scale system.

[0142] This system may be scaled up to increase total throughput of slag by adding additional means for directing the at least one fluid stream, for example, to result in multiple fluid streams impinging the molten calciferous material through a common axis. Additional molten material streams may be added, or the length of the planar sheet may be increased to increase molten material throughput.

[0143] Integrated Industrial System

[0144] In some particular embodiments, the atomisation system of the first or second aspects of the invention may be further integrated into an industrial system.

[0145] In such embodiments the integrated system may have a slag pot directly integrated to provide the molten calciferous material. The slag pot may itself be directly integrated into an industrial facility.

[0146] The slag pot may be provided on a tipping platform. The tipping platform may be at an elevated height, for example about 2 to 3 m. The provision of a slag pot on a tipping platform is effective to enable the pouring of the molten calciferous material either directly or indirectly into an atomisation system according to the first or second aspects of the invention. The slag pot itself may be tippable.

[0147] In preferred embodiments the slag pot indirectly pours the molten calciferous material. By "indirectly" pours it is meant that the molten material is poured into intermediate vessels or reservoirs, which themselves provide pouring means. The integrated system may comprise a multiplicity of intermediate vessels or reservoirs, arranged in series and / or in parallel to one another.

[0148] Advantageously by having a multiplicity of intermediate vessels or reservoirs, the flow rate of molten calciferous material may be controlled, for example slowed, from the initial slag pour rate, to a controlled rate into the atomisation system. Each intermediate vessel or reservoir may be equipped with heating means to maintain the molten material at a required temperature, and / or mixing means, such as a stirrer, for maintaining the molten calciferous material as a homogeneous mixture.

[0149] Each intermediate vessel or reservoir may be equipped with a tipping means, to enable the pouring of molten material to the subsequent vessel or reservoir, or each intermediate vessel or reservoir may be equipped with an outlet to produce a stream of molten material to the subsequent vessel or reservoir. In such an embodiment, the outlet may comprise a flow path for the molten material to flow along, such as for example a chute, which is a sloping channel for conveying things for a lower level.

[0150] The "intermediate vessel or reservoir" is to be understood as a means for holding or storing a molten calciferous material, examples of which may include, but are not limited to, a container, a tank, or any other suitable means in the art. The reservoir may include a singular reservoir, or more than one reservoir.

[0151] In a preferred embodiment, the integrated system may comprise a tippable slag pot, a first intermediate reservoir, a second intermediate reservoir, and an atomisation system according to the first or second aspect of the invention, wherein the tippable slag pot pours molten material into the first intermediate reservoir, and the molten material controllably flows from the first intermediate reservoir to the second intermediate reservoir by means of a first chute, and then from the second intermediate reservoir to the atomisation system by a second chute. The integrated system thus provides a means for transferring molten material from the tippable slag pot to the atomisation system in a controlled manner.

[0152] The pour rate from the slag pot to the first intermediate reservoir may be from about 1 to about 2 tonnes per minute.

[0153] The flow rate from the first or second intermediate reservoir may be from about 0.2 to about 1.8 tonnes per minute, preferably from about 0.2 to about 1 tonnes per minute, more preferably from about 0.2 to about 0.5 tonnes per minute, wherein the flow rate from the second intermediate reservoir is lower than the flow rate from the first intermediate reservoir. The flow rate from the second intermediate reservoir to the atomisation system may be from about 0.1 to about 0.3 tonnes per minute, preferably 0.1 to about 0.2 tonnes per minute.

[0154] The intermediate vessels or reservoirs may be supported on metal frameworks, such as steel frameworks, or any other suitable support means known in the art.

[0155] Process

[0156] According to the invention, there is provided a process for atomising a molten calciferous material.

[0157] The process of the present invention may be operated on an apparatus or system according to the first or second aspects discussed herein. Therefore, all features relating to the apparatus and / or system of the present invention may apply, where appropriate, to the process.

[0158] The process may further include cooling the atomised particulate material to produce a cooled atomised particulate material; and collecting the cooled atomised particle in a collecting means. The cooling of the atomised particulate material may be rapid cooling.

[0159] Rapid cooling of the atomised particulate material has been found to produce particles with a high fraction of amorphous phases. Therefore, if the atomised particulate material is mixed with other materials, for example cementitious materials, the increased amorphous content has been found to rapidly react and increase the resultant strength of the material.

[0160] Whilst processes such as granulation of blast furnace slags are known, the processes known in the art do not address the significantly faster cooling rates required for molten slags to achieve the correct mineralogy to exhibit favourable cementitious behaviour. Advantageously, the fluid stream, either alone, or when coupled with additional cooling means, provides a process which enables the production of a fine and tuneable particle size distribution of slag particles that are able to be rapidly quenched to generate the optimal reactive content, with a balance of amorphous, cementitious minerals, and inert materials.

[0161] The at least one molten material stream may be provided as a continuous sheet of molten calciferous material. In alternative embodiments, the at least one molten stream may be provided as a multiplicity of discrete molten calciferous material streams. The multiplicity of discrete molten material streams may be provided discrete separate streams, or may be in an arrangement such that the discrete molten material streams provide a sheetlike stream

[0162] The collecting means may include means for collecting the material ( i.e., storage means, solid plate or surface) and / or means for further processing of the collected material (i.e., into a water bath, or into further jets). In preferred embodiments, the atomised material may be collected by means of a solid plate / surface or a water bath.

[0163] The atomised particulate material may be a spray of fine droplets.

[0164] In alternative embodiments, the atomised material may be passed through further at least one fluid streams and subsequently collected by the collecting means. Advantageously, repeating the process through multiple sets of fluid streams generates finer atomised material products.

[0165] In some embodiments, the process according to the third aspect of the invention may further comprise the following steps:

[0166] (v) filtering and drying the atomised particulate material;

[0167] (vi) further processing the atomised particulate material; and / or

[0168] (vii) collecting waste fluid from the process.

[0169] Further processing of the atomised material may comprise grinding and / or chemical treatment.

[0170] Thus, in some embodiments, the process may further comprise an additional step of grinding the particulate material to reduce the average particle size as required, and the additional grinding step may be included at any point after atomisation, such as directly after the atomisation step, or alternatively as a final processing step of the supplementary cementitious material.

[0171] In some embodiments of the present invention at least one additional grinding step may be included. The particles produced may be fine particles. The fine particles produced by an additional grinding step may be from about 2 pm to about 20 pm, from about 5 pm to about 10 pm, from about 5 pm to about 15 pm, from about 5 pm to about 20 pm, from about 10 pm to about 20 pm or from about 15 pm to about 20 pm in diameter. In a preferred embodiment the fine particles produced by an additional grinding step may be about 20 pm in diameter, in the form of a fine powder. Waste fluid collected from the process may comprise collecting fluid following filtration from the atomised material, or residual fluid from the at least one fluid stream. The waste fluid may be treated and / or recycled. The waste fluid may be recycled and used in the at least one fluid streams.

[0172] In some embodiments, the heat of the process will cause the fluid to be vaporised and converted to the gaseous phase.

[0173] In particular embodiments, where the fluid stream is water, at least a portion of the at least one water stream will be converted to steam. The steam may be recovered and recycled for further use.

[0174] Advantageously, the process of rapidly cooling the calciferous material concurrently removes heat. Heat may be removed by the fluid stream. Recovered heat may be recycled and used in further processes, such as, for example, drying the atomised particulate material.

[0175] In some embodiments, the process may be powered using renewable energy. Renewable energy may be energy derived from any suitable renewable energy source, including but not limited to wind, solar, tidal or biomass.

[0176] In some embodiments, the process may be monitored and controlled by a monitoring system and said system may collect data, such as, for example, spectroscopic, micrographic, thermal or diffractive data.

[0177] The composition of the molten calciferous material, and in particular steel slag when such is used as the feedstock or as part of it, can vary significantly (e.g., from steelworks to steelworks), so the reaction conditions need to be adaptable. Therefore, in some embodiments of the present invention, the data collected from the monitoring system may be analysed by machine learning techniques to control the reaction conditions. The machine learning techniques may be applied in combination with sample analysis, such as X-ray diffraction and X-ray fluorescence.

[0178] Advantageously, by monitoring and controlling the molten calciferous material feedstock, atomisation process, and atomised product, a more consistent product can be produced, with properties tailored to the desired end application, which is especially beneficial for applications of the atomised product as a supplementary cementitious product. Molten Calciferous Material

[0179] Slag is a by-product formed in smelting, welding, and other metallurgical and combustion processes from impurities in the metals or ores being treated. Slag predominantly comprises mixed oxides of elements such as silicon, sulphur, phosphorus, and aluminium; ash; and products formed in their reactions with furnace linings and fluxing substances such as limestone. For example, it is mainly composed of SiC and CaO, includes AI2O3, FeO, MgO, P2O5 and CaS, depending on the type of refining process that had been employed

[0180] In pyrometallurgical processes, such as those carried out in the steelmaking process, slag floats on the surface of the molten metal. Variants of slag are often further defined by reference to the type of precursor and / or processing conditions used to produce them, such as blast furnace (BF) slags basic oxygen furnace (BOF) slag, and electric arc furnace (EAF) slag. During metal production, slag is present in the metallurgical furnace in molten form, and typically molten slag is periodically or continuously tapped from the furnace for disposal and / or further processing.

[0181] Steel slag is a waste material created as a by-product of steel production, particularly when molten steel is separated from impurities in a basic oxygen furnace (BOF) or electric arc furnace (EAF). Steel slag is typically a complex mixture of silicates and oxides that solidifies into a solid material when it cools, which is rich in metal oxides and other minerals. The physical and chemical properties of the material are affected by its chemical composition and how it's cooled. Steel slag can be used as a cementing component in various cementing systems, for example it can be used in place of conventional cements in many applications, including road construction. As described in embodiments of the invention, steel slag can be carbonated to store CO2 and improve its properties as a construction material.

[0182] Currently, low carbon steel is produced by methods that alter the steelmaking process itself. Steel can be produced via two main processes: either using an integrated blast furnace (BF) / basic oxygen furnace (BOF) or an electric arc furnace (EAF). Efforts to decarbonise the industry largely seek to improve the efficiency of these processes, or to use alternate fuel sources, such as biomass or hydrogen, rather than the conventional coal. For example, current efforts include using hydrogen in the direct reduction of iron (DRI) and increasing the amount of steel recycling using electric arc furnaces. However, these approaches are also challenging. For example, DRI requires orders of 1 magnitude more green hydrogen than is currently produced worldwide, as well as large capital investment. Furthermore, only 2.5% of current iron ore production is suitable for DRL

[0183] Electric arc furnaces may be used for steel recycling, but if the electricity used to power such furnaces is not in itself carbon neutral, no ultimate reduction of the carbon footprint results. The use of EAF for recycling uses less energy than BF-BOF processes because it is not a primary steelmaking process. Despite its advantages, EAF still has a considerable carbon footprint, mainly because they often use some fossil fuels, such as oxyfuels, in their heating processes. Additionally, since EAF steelmaking mainly uses recycled materials such as scrap iron and scrap steel, the resulting EAF slag and dust can be toxic. EAF dust frequently contains toxic elements, persistent organic pollutants, or dioxins, and is categorized as a hazardous industrial waste.

[0184] Copper slag is a glassy, granular, or lumpy by-product of copper smelting that contains valuable metals and hazardous elements. For example, copper slag is typically made up of iron, silica, alumina, calcium oxide, and other elements. The chemical composition varies depending on the furnace and treatment process. Copper slag can be used as an aggregate in cement and concrete, which can provide environmental and economic benefits.

[0185] Cooled slag has two solid phases: a crystalline phase is formed when slag is cooled slowly, and a glassy phase (amorphous phase) is formed when slag is cooled quickly. During a rapid cooling process, the substances in the molten slag do not have time to form stable crystalline compounds, and the thermal energy that cannot be released is converted into chemical energy stored in the state of glass, thus having potential chemical activity, and making the amorphous material highly reactive. Therefore, rapidly cooled slag has favourable cementitious properties and may be used as a supplementary cementitious material.

[0186] The physical properties of steel or copper slags may be altered to improve the cementitious nature of the slag and improve the suitability of the material for cement applications. Whilst it is known that the properties of steel or copper slags may be altered through chemical reaction, such as calcination, challenges concerning the free lime content in the slag are the cause of volume instabilities. Alternatively, as demonstrated by the invention, the physical properties may be altered by atomisation. The molten calciferous material may be a steel slag or a copper slag. For example, the molten calciferous material may be a molten slag obtained directly from a steelmaking process, or it may be remelted air-cooled slag. The molten calciferous material may be provided with supplementary materials, for example but not limited to, silica, metal oxide powders, reductants (such as aluminium or graphite) or oxygen, to improve the atomisability of the waste material and cementitious properties.

[0187] Advantageously, a process using such feedstocks aids in the reduction of carbon emissions, through the upcycling of waste that otherwise would be difficult to recycle. In turn this results in lower handling costs. Particularly, steel slags, which previously could only be recycled as aggregates in road construction or sent to landfill, may now be able to generate revenue and contribute to the circular economy.

[0188] The reservoir may be directly attached to a steelmaking facility or may be located separately.

[0189] The molten calciferous material (i.e., steel or copper slag) may be obtained from an electric arc furnace, a basic oxygen furnace, a blast furnace, or any other conventional steelmaking facility. In preferred embodiments, the molten calciferous material is obtained directly from such facilities. Advantageously, the use of molten slag-based feedstocks from direct from a furnace, as opposed to solidified slags, which have to be re-melted, requires significantly less energy. Particularly, the use of a molten steel slag feedstock from a steelmaking facility in the process is able to significantly reduce the overall net emissions of the steelmaking process. Similarly, the use of a copper slag calciferous feedstock from a smelting facility in the process is also able to significantly reduce the overall net emissions of the copper smelting process.

[0190] In embodiments where the molten calciferous material is a molten steel or copper slag, or remelted air-cooled slag, the slag temperature may be from about 1000 °C to about 2000 °C, from about 1300 °C to about 2000 °C, about 1300 °C to about 1800 °C, about 1300 °C to about 1700 °C, about 1400 °C to about 1600 °C or about 1400 °C to about 1500 °C. In a preferred embodiment, the temperature of the molten calciferous material may be about 1500 °C.

[0191] In some embodiments, the calciferous feedstock may be doped with additional material. Preferably, the additional material is selected from silica, elemental metals, metal oxide powders, reductants, or oxygen, however, the skilled person would know and be able to select any suitable dopant to add as additional material to alter or improve the cementitious properties of the calciferous feedstock.

[0192] Atomised Particulate Material

[0193] According to the invention, there is provided an atomised particulate material, produced by the apparatus or system, or by the process according to the invention.

[0194] The at least one fluid stream atomises the at least one molten material stream to produce an atomised particulate material, as a result of the impingement of the fluid stream with the molten material stream.

[0195] The atomised particulate material may have increased amorphous content, and / or reduced crystal size. This is because the apparatus and process of the present invention provides an atomisation process that generates smaller particles that cool faster, and as a result the particles are less crystalline and more amorphous, or glass.

[0196] The atomised particulate matter is preferably amorphous. In a preferred embodiment, the particulate matter may be greater than about 50%, about 60%, about 70%, about 80% or about 90% by weight amorphous.

[0197] The atomised particulate material may have an average glass content of about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, or about 98%.

[0198] Typically, the smaller the particle size, the higher the glass content achieved. However, this will also depend on the composition of molten calciferous material used as a feedstock.

[0199] In contrast, conventional methods of granulation generate larger particles, which cool more slowly, and are crystalline in nature. Additionally, in conventional technology slag is tipped and / or tapped off the furnace and left to cool on the ground, and the resulting mineralogy is not particularly cementitious.

[0200] The atomisation of the at least one molten material stream by the impingement of the at least one fluid stream, results in the rapid quenching of the material. Thus, the atomised particulate material may be rapidly quenched, for example, in a water bath. It has been found that when quenched rapidly the material can undergo a phase transition, increasing their amorphous / glass content and the resulting metastable structure has improved reactivity. It has been found that the apparatus of the invention can beneficially control the amount of momentum transfer of the at least one fluid stream to the molten calciferous stream, for it's atomisation into an atomised particulate material.

[0201] By "rapidly quenched", we mean for preference that the molten calciferous feedstock is simultaneously cooled and comminuted under conditions effective to generate an at least partly amorphous, preferably at least 50% by weight amorphous, particulate material.

[0202] Advantageously the rapid cooling of the molten calciferous material produces a high fraction of amorphous phases within the atomised material structure. When ground and mixed with other cementitious materials, this amorphous content will react rapidly and contribute to enhancing the resultant strength of the material.

[0203] Further advantageously, atomisation as a size reduction technique can reduce the energy consumption by up to 94% versus traditional comminution techniques and size reduction of calciferous feedstock slag increases surface area and creates highly reactive minerals. Additionally, rapid quenching of the molten calciferous material in this manner is able to generate a highly amorphous, hydraulic material, which is more suitable for use in mineralisation processes than known processes in the art.

[0204] In embodiments of the invention, the atomised particulate material may be a spray of fine droplets.

[0205] The size of the atomised particulate material may be less than about 1000 pm Jess than about 700 pm, less than about 500 pm, less than about 400 pm, less than about 300 pm, less than about 200 pm, less than about 150 pm, or less than about 100 pm.

[0206] The size of the atomised particulate material may be from about 20 pm to about 3000 pm, from about 20 pm to about 1000 pm, from about 20 pm to about 700 pm from about 20 pm to about 500 pm, from about 20 pm to about 200 pm, from about 20 pm to about 100 pm, from about 50 pm to about 200 pm, from about 50 pm to about 150 pm, from about 50 pm to 20 about 100 pm, or from about 80 pm to about 100 pm in diameter. The inventors have found that this particulate size advantageously allows the particulate material and / or droplets to rapidly cool down and produce a high fraction of amorphous phases within the calciferous material and is best suited for use as a SCM.

[0207] In a particular embodiment of the invention, about 80% of the atomised particulate material may be less than about 700 pm, less than about 600 pm, or less than about 500 pm.

[0208] In a preferred embodiment, the particulate material may comprise particles of about 500 pm or less in diameter. The person skilled in the art will appreciate that there may be a trade-off between processing a high feedstock throughput and providing a relatively small particle size (which will aid subsequent processing / reaction of the particulate material). The specific preferred particle size will therefore depend to some extent on the end application.

[0209] The atomised particulate material may be further ground and / or chemically treated.

[0210] In some embodiments of the present invention, when at least one additional grinding step is included, the atomised particulate material may be provided as fine particles. The fine particles produced by an additional grinding step may be from about 2 pm to about 20 pm, from about 5 pm to about 10 pm, from about 5 pm to about 15 pm, from about 5 pm to about 20 pm, from about 10 pm to about 20 pm or from about 15 pm to about 20 pm in diameter. In a preferred embodiment the fine particles produced by an additional grinding step may be about 20 pm in diameter, in the form of a fine powder.

[0211] According to the invention, there is provided the use of an atomised particulate material according to the fourth aspect as a supplementary cementitious material.

[0212] The supplementary cementitious material may be used to produce a blend with cement, which may be used in the production of concrete.

[0213] Supplementary cementitious material (SCM) is a material that can be added to concrete mixtures in addition to, or as a partial replacement of, traditional Portland cement or blended cements to improve both fresh and hardened concrete properties.

[0214] SCMs may be added to alter properties of the overall cement blend, including durability, permeability, pumpability and finishability, mitigating alkali reactivity and the overall hardened properties of concrete through hydraulic or pozzolanic activity (or both). Currently, SCMs have a great variability in their physicochemical properties, which presents a distinct challenge for their application in cement production as this introduces uncertainty in end product strength.

[0215] Therefore, provision of a consistent SCM, whose production is both scalable and controllable would be greatly advantageous and would enable increased use of SCMs in cement mixes. SCMs may be designed to increase long term strength, as well as increase durability, by reducing permeability. Increased SCM content may also delay set time by slowing the rate of hydration. This is helpful during hot weather but may not be in cooler weather. SCM addition also reduces risk of thermal cracking by lowering peak hydration temperatures.

[0216] Figures

[0217] The invention will now be more particularly described with reference to the following examples and figures, in which;

[0218] Figure 1 shows a simplified flow diagram which describes the process according to an embodiment of the present invention;

[0219] Figure 2 shows a detailed process flow diagram of the process in accordance with an embodiment the present invention;

[0220] Figure 3 shows a schematic view of an atomiser in accordance with an embodiment of the present invention, from both a side view (3A) and an isometric view (3B);

[0221] Figure 4 shows a graph detailing the cumulative particle size distribution of an atomised steel slag sample by the process of the invention;

[0222] Figure 5 shows a graph detailing the relationship between the glass content of the particle and the particle size;

[0223] Figures 6A to 6E show schematic views of an atomiser in accordance with embodiments of the present invention from a side view; and Figure 7 shows a graph detailing the variation of glass content with pressure for different molten calciferous material compositions.

[0224] Referring to Figure 1, there is shown a simplified flow diagram which describes the process according to an embodiment of the present invention. Industrial waste material (101), in the form of steel slags is provided to an atomiser (102). The waste material may also be supplemented by additional materials (103), such as silica, metal oxide powders, reductants (such as aluminium or graphite) or oxygen, added to alter and improve the atomisability of the waste material and cementitious properties. The atomization process is rapidly quenched by a stream of water (104) provided to the atomiser. The stream of water may comprise highly pressurized water. The residual wastewater (105) is removed and may be treated and recycled. The resultant particulate product (106) may be further quenched with further water streams or in a water bath (107), and passed to further processing steps, such as grinding or milling (108) to produce a fine particulate product (109).

[0225] Referring to Figure 2, there is shown a detailed process flow diagram of the process in accordance with an embodiment the present invention. Molten slag (201) is poured into a slag crucible (202), where it is doped with additional material (1), such as silica, alumina or reducing agents to improve its cementitious behaviour and atomisability. Doped molten slag (2) is transferred to an atomiser (203), where it is atomized to an atomized powder (4). The atomization process may convert the slag into particles of sizes of approximately 500 pm, by passing the molten liquid through a pressurised stream of water (3) which rapidly quenches the molten liquid. Wastewater (5) is removed and sent to a water treatment plant (204), where pollutants are removed, to produce treated wastewater (6). The stream of water (3) may comprise recycled water collected either from downstream processes or treated wastewater (6) from the atomization process. Hot off gas (7) from the atomization process is vented and may be used in downstream heat recovery processes. Atomised powder (4) is transferred to a grinding mill (205) in which it may be ground down to a particle size of approximately 20 pm, to produce a cementitious product (206), which is outputted from the system.

[0226] Referring to Figure 3, there is shown a schematic view of an atomiser in accordance with an embodiment of the present invention, from both a side view (3A) and an isometric view (3B). Figure 3A shows an atomisation system where industrial waste material (301), in the form of molten steel slags is provided to a container, such as slag crucible (302), which has an outlet (303). The waste material may also be supplemented by additional materials, such as silica, metal oxide powders, reductants (such as aluminium or graphite) or oxygen, added to alter and improve the atomisability of the waste material and cementitious properties. The material is rapidly quenched by a stream of water, where high pressure water pumps (304) each produce pressurised water jets (305), which converge at an impingement point (306). The jets may be fan jets produced from a nozzle, such as a fan nozzle. The molten material is poured from the crucible (302), by means of outlet (303), to produce a molten material stream (307), which is directed to the impingement point (306). As the molten material passes through the converging high pressure water jets (305) at the impingement point (306), the material is rapidly quenched to produce atomised material (308), which is highly amorphous and may be collected in a trough, or other suitable container. Figure 3B shows a simplified version of the atomisation system from an isometric view. Shown are shown the high-pressure water jets (305) and molten material streams (307), in series with one another, so as to form sheets of pressurised water and molten material, respectively. Interaction of the sheet of molten material (307), with the converging sheets of pressurised water (305), produces the atomised material (308).

[0227] Referring to Figures 6A to 6E, these show schematic views of atomisers in accordance with different embodiments of the present invention. It will be understood by the skilled person that the industrial waste material provided and the jets used is the same as that described for Figure 3A, unless otherwise stated.

[0228] Referring to Figure 6A, there is shown a schematic view of an atomiser in accordance with an embodiment of the present invention, from a side view. Figure 6A shows an atomisation system wherein the system is the same as that described in Figure 3A, wherein the arrangement of the high pressure water pumps (604) differs. The industrial waste material (601), in the form of molten steel slags is provided to a container, such as slag crucible (602), which has an outlet (603). The waste material may also be supplemented by additional materials, such as silica, metal oxide powders, reductants (such as aluminium or graphite) or oxygen, added to alter and improve the atomisability of the waste material and cementitious properties. The material is rapidly quenched by a stream of water, where high pressure water pumps (604) each produce pressurised water jets (605), which converge at an impingement point (606). The jets may be fan jets produced from a nozzle, such as a fan nozzle. The molten material is poured from the crucible (602), by means of outlet (603), to produce a molten material stream (607), which is directed to the impingement points (606). As the molten material passes through the high pressure water jets (605) at the impingement points (606), the material is rapidly quenched to produce atomised material (608), which is highly amorphous and may be collected in a trough, or other suitable container. In this embodiment, there are two high pressure water pumps (604) that are located on opposite sides of the molten material stream (307) which are not symmetrical with respect to one another. The high pressure water jets (605) impinge the molten material stream at two different points. In this embodiment, there are therefore two impingement points (606). In this embodiment, there is a series of atomisation of the molten material stream (607).

[0229] Referring to Figure 6B, there is shown a schematic view of an atomiser in accordance with an embodiment of the present invention. The arrangement in this embodiment shows the presence of three high pressure water pumps (604). Two of the water pumps impinge the molten material stream (607) at the same point and converge with one another, and a third water pump impinges the molten material stream (607) at a further impingement point (606). In this embodiment, there is a series of atomisation of the molten material stream (607).

[0230] Referring to Figure 6C, there is shown a schematic view of an atomiser in accordance with an embodiment of the present invention. The arrangement in this embodiment shows the presence of three high pressure water pumps (604). A first water pump (604) rapidly quenches the molten material stream (607) to produce atomised material (608) at a first impingement point (606) which is further quenched at a second impingement point (606) created by the convergence of a pair of high pressure water pumps (604) to produce further atomised material (608), which is highly amorphous and may be collected in a trough, or other suitable container.

[0231] Referring to Figure 6D, there is shown a schematic view of an atomiser in accordance with an embodiment of the present invention. The arrangement in this embodiment shows the presence of a pair of high pressure water pumps (604). A first pair of water pumps (604) rapidly quenches the molten material stream (607) at an impingement point (606) to produce atomised material. This embodiment also comprises a high pressure solid cone spray nozzle (609). The solid cone spray nozzle (609) is arranged in a counterflow direction and atomises any larger slag particles which may have been missed or skipped over the first pair of high pressure jets (604).

[0232] Referring to Figure 6E there is shown a schematic view of an atomiser in accordance with an embodiment of the present invention. The arrangement in this embodiment shows the presence of four high pressure water pumps (604), wherein there are two sets of pairs of high pressure water pumps (604). A first pair of water pumps (604) rapidly quenches the molten material stream (607) at an impingement point (606) to produce atomised material which is further quenched at a second impingement point (606) created by the convergence of a second pair of high pressure water pumps (604), to produce additional atomised material (608), which is highly amorphous and may be collected in a trough, or other suitable container.

[0233] EXAMPLE 1

[0234] A molten steel slag was atomised into two impinging planar water jets, produced by a total of 4 nozzles. In this setup, the nozzles were running at a water pressure of 70 bar and a flow rate of 4 L / min.

[0235] The resultant atomised particles were recovered, and their particle size distribution recorded. The PSD was determined by using a series of sieves of decreasing sizes.

[0236] The particle size distribution is shown in Figure 4, which shows the cumulative particle size distribution of the atomised steel slag sample.

[0237] The amorphous content was assessed for different particle sizes, and the relationship between them is shown in Figure 5, which clearly shows that the smaller the particle size, the higher the glass content of the particles.

[0238] EXAMPLE 2

[0239] A series of experiments were conducted on an arrangement as shown in Figure 3, for the atomization of molten calciferous materials into supplementary cementitious material. Two high-pressure impinging water jets were directed towards a molten slag stream exciting a crucible nozzle. The inclination angle of the jets were fixed at 40°, and atomisation trials were conducted over a range of pressures between 50 and 250 bar and total water flow rates between 10 and 18 L / min.

[0240] It was found that this arrangement, including any upstream equipment, processed molten slag at a rate of 0.4 kg / s for 2 to 4 seconds per pouring cycle.

[0241] This example demonstrated that, for a given slag composition, there is an optimum operating pressure at which the glass content of the atomised slag is maximised (as shown more clearly in Figure 7). The resultant atomised material exhibited an average particle size range of 150-750 pm, which was subsequently ground to a specified fineness for supplementary cementitious material applications.

[0242] Cement cubes were then prepared using a formulation containing 30-50 wt.% supplementary cementitious material replacement, resulting in compressive strengths in the range of 28-55 MPa. These results validated the feasibility of the atomisation process in producing reactive, glass-rich particles suitable for use as supplementary cementitious materials.

[0243] EXAMPLE 3

[0244] A series of experiments were conducted on an arrangement as shown in Figure 6B. This was tested to measure the momentum utilisation of the impinging high-pressure jets and enhance throughput capacity.

[0245] A modified three-jet atomizer system was used. This configuration employed three converging high- pressure water jets, operated within a pressure range of 150-200 bar and a total water flow rate of 16.5-20 L / min. The inclination angle of the impinging jets varied between 10° and 50°, and the vertical offset between the upper and lower jets was maintained between 15-30 cm.

[0246] Under these conditions, it was found that this configuration achieved approximately 30% higher jet momentum utilisation compared to that achieved in Example 2, and enabled a slag processing rate of 0.5 kg / s for 2 to 4 seconds per cycle. The slag sample used (i.e., the glass content, average particle size and cube strength) were comparable to those obtained in Example 2.

[0247] The enhanced jet geometry in this configured improved atomisation uniformity and maintained stable operation across the tested pressure range.

[0248] EXAMPLE 4

[0249] Using the same three-jet atomizer system as detailed in Example 3, a dual-stream molten slag feed, with an increased throughput capacity of 1 kg / s and operation times of 20-50 seconds per cycle was employed. In this configuration, the momentum utilisation of the high-pressure jets was doubled relative to the small-scale system, resulting in an approximate 50% reduction in high-pressure water consumption. Cooling water was circulated continuously to maintain a water-to-slag mass ratio of approximately 5:1 creating a water bath for rapid cooling.

[0250] The molten slag was atomised, quenched, and collected as a slurry, which was continuously dewatered using a mechanical dewatering system. The slag sample included between 40-50% of the glass content, had an average particle size of between 400 and 500 pm and a compressive cube strength between 28-32 MPa.

[0251] EXAMPLE 5

[0252] A series of experiments were conducted on an arrangement wherein four sets of the configuration of Example 3 (i.e., Figure 6B), were arranged horizontally to form a modular array and a larger scale atomizer.

[0253] The large-scale atomiser achieved a combined throughput of 2 kg / s with operation durations between 250 and 500 seconds per pouring cycle. The system processed 500-1000 kg of molten slag per batch. The cooling water was continuously circulated, and the overall water-to-slag ratio was reduced to approximately 4:1. The setup incorporated a slag collector tank and a sedimentation tank for enhanced recovery of fine atomised material. The sedimentation tank also served to maintain a constant hydraulic head within the collector, ensuring uniform quenching and high cooling rates.

[0254] For the selected EAF (non-metallic by-product) slag, the glass content ranged between 60-65%, the average particle size between 400-500 pm, and the compressive cube strength between 30-46 MPa.

[0255] The results demonstrated successful scale-up while maintaining glass phase content and material reactivity comparable to the small-scale trials.

[0256] Table 1 summarises the performance of the different atomizer configurations.

[0257] TABLE 1

[0258] The results of Table 1 confirms the scalability of the atomisation architecture, with consistent product characteristics across multiple orders of throughput magnitude.

Claims

1. CLAIMS1. An apparatus configured to operate a process for the atomisation of a molten calciferous material, the apparatus comprising: a reservoir for containing a molten calciferous material, the reservoir comprising an outlet to produce at least one molten calciferous stream; and means for directing at least one fluid stream at the molten calciferous stream such that the at least one fluid stream impinges the molten calciferous stream at an angle effective to atomise the molten calciferous stream to produce an atomised particulate material; wherein the outlet is configured to provide the molten calciferous stream as a linear stream; and wherein the means for directing the at least one fluid stream comprises a series of directing means configured to direct multiple pressurised fluid streams to impinge the at least one molten calciferous stream on its opposite sides.

2. The apparatus according to Claim 1, wherein the linear stream of molten calciferous material is a continuous sheet of molten calciferous material, or a multiplicity of discrete molten calciferous material streams.

3. The apparatus according to Claim 1 or Claim 2, wherein the series of fluid streams comprises at least 2 fluid streams, at least 3 fluid streams, or at least 4 fluid streams.

4. The apparatus according to any one of Claims 1 to 3 wherein the angle between the at least on fluid stream and the molten calciferous stream is between about 10° and 160°, between about 20° and 120°, between 30° and about 80°, between about 40° and 60°.

5. The apparatus according to any one of Claims 1 to 4 wherein the outlet is a nozzle, optionally a linear slot nozzle, a weir, or any other suitable means.

6. The apparatus according to any one of Claims 1 to 5, wherein the at least one fluid stream is generated by a nozzle, optionally a fan nozzle.

7. The apparatus according to any one of Claims 1 to 6 wherein the fluid stream impinges the linear molten calciferous stream substantially continuously across several points.

8. The apparatus according to any one of Claims 1 to 7 , wherein the at least one fluid stream is selected from water, oil, or a gas, or any compatible mixture thereof.

9. The apparatus according to any one of Claims 1 to 8, wherein the pressure of the at least one fluid stream may be at least about 5000000 Pa, at least about 6000000 Pa, at least about 8000000 Pa, at least about 10000000 Pa, at least about 15000000 Pa, or at least about 20000000 Pa .

10. The apparatus according to any one of Claims 1 to 9, wherein the ratio of the flow rate of the at least one molten calciferous stream to the flow rate of the at least one fluid stream may be between about 10:1 and about 1:10, about 10:1 and about 1:1, or between about 5:1 and about 1:

111. The apparatus according to any one of Claims 1 to 10, wherein the molten calciferous material feedstock is a steel slag or a copper slag, optionally wherein the steel slag is obtained from an electric arc furnace, a basic oxygen furnace, a blast furnace, or any other conventional steelmaking facility.

12. The apparatus according to any one of Claims 1 to 11, wherein the apparatus further comprises a collecting means to collect the atomised particulate material, optionally wherein the collecting means comprises a solid plate or surface, a water bath, or additional fluid streams.

13. The apparatus according to Claim 12, wherein the atomised particulate material is cooled prior to collection by the collecting means or by the collecting means.

14. A system for the large-scale atomisation of molten calciferous material comprising a multiplicity of apparatuses according to any one of Claims 1 to 13.

15. The system according to Claim 14, wherein the multiplicity of apparatuses comprises at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, or at least ten apparatuses according to any one of Claims 1 to 13.

16. The system according to either Claim 14 or Claim 15, wherein the multiplicity of apparatuses are arranged in series or in parallel with one another, and / or wherein the multiplicity of apparatuses are modular.

17. A process for atomising a molten calciferous material, the process comprising: a. providing at least one stream of molten calciferous material from an outlet of a reservoir; and b. directing at least one fluid stream at the stream of molten calciferous material such that the at least one fluid stream impinges the molten calciferous stream at an angle effective to atomise the molten calciferous stream to produce an atomised particulate material.

18. The process according to Claim 17 wherein the process further comprises: cooling the atomised particulate material to produce a cooled atomised particulate material; and collecting the cooled atomised particle in a collecting means.

19. The process according to any one of Claim 17 or 18 wherein the molten calciferous stream is a continuous sheet of molten calciferous material, or a multiplicity of discrete molten calciferous material streams.

20. An atomised particulate material, produced by the apparatus or system according to any one of Claims 1 to 16, or the process according to any one of Claims 17 to 19.

21. Use of an atomised particulate material according to Claim 20 as a supplementary cementitious material.

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