METHOD OF TREATMENT OF BLACK STEELWORK SLAG FOR USE IN HYDRAULIC FRACTURING

Description

METHOD OF TREATMENT OF BLACK STEELWORK SLAG FOR USE IN HYDRAULIC FRACTURING The present invention relates to a method of 5 treatment of black steel mill slag for use in hydraulic fracturing. More specifically, the invention refers to a method of preparing a proppant used for hydraulic fracturing from black slag 10 of steelworks. Field of invention The invention falls within the technical field of methods for energy production, particularly in technical field of fracturing systems 15 hydraulics. On the other hand, the invention also refers to the steel and steelmaking technical field. Known technique Hydraulic fracturing, traditionally known 20 even with the name “fracking”, it is a technique that is used for the extraction of oil and natural gas from underground rock formations. More specifically, this technique involves the injection of a mixture at high pressure 25 containing water, chemicals and proppant inside a well. This injection causes fractures in the rocks which allow the flow of hydrocarbons and subsequently their extraction. BR / AZAC / A220428-00 Nowadays, as a proppant it is generally used silica sand (silica sand) because of its compressive strength properties and shatter resistance. 5 Disadvantageously, the extraction and the necessary silica sand processing brings challenges significant environmental and economic impacts. In fact, its extraction and processing are a source have a significant environmental impact and require a 10 considerable expense. There is therefore a need in the sector to find an alternative solution to silica sand that can be more economical and sustainable by allowing the replacement of silica sand in the processes 15 hydraulic fracturing. Furthermore, the recycling or reuse of waste steel mill would lead to a significant reduction in environmental impact compared to their traditional disposal. 20 The treatment of such waste can in fact be also significantly expensive economically and can also have a high environmental impact. Purpose of the invention The aim of the present invention is therefore to 25 provide a method of treatment of black slag steel mill for use in hydraulic fracturing able to solve problems and critical issues above mentioned. Another purpose of the present invention is to 30 to develop a method of treating black slag BR / AZAC / A220428-00 steel mill for use in hydraulic fracturing which allows the reuse of steelworks slag and in detail of black slag. A further aim of the present invention is to 5 to provide a method of treating black slag steel mill for use in hydraulic fracturing that is sustainable and promotes the circular economy. Another purpose of the present invention is to to develop a method of treating black slag 10 steel mills for use in hydraulic fracturing that is economically advantageous. A further object of the present invention is to provide a method of waste treatment black steel mill for use in fracturing 15 hydraulics that reduce costs and environmental impact of the fracturing technique. Another purpose of the present invention is to to develop a method of treating black slag steel mill for use in hydraulic fracturing 20 which can provide an alternative to sand silica. A further object of the present invention is that of creating a method of treatment of the black steel mill slag for use in 25 hydraulic fracturing that is easy and economical realization and use by virtue of the advantages achieved. These and other goals are achieved by a method of treatment of black steelworks slag for BR / AZAC / A220428-00 the use in hydraulic fracturing according to the independent claim attached. Further detailed technical features are reported in the attached dependent claims. 5 Detailed description In the following description, a preferred embodiment of a method of treatment of black steelworks slag for use in hydraulic fracturing. 10 The method of using black slag of steel mill in hydraulic fracturing, object of the invention, in its first embodiment, has the goal of reducing costs and environmental impact of hydraulic fracturing techniques. 15 In particular, the method of the present invention proposes to reuse black steel slag as an economical and sustainable alternative to sand siliceous offering numerous advantages in multiple wait. 20 In more detail, the method according to the invention It is proposed to process the black slag from steelworks in so as to modify its properties making it suitable for the replacement, at least partial, of silica sand in hydraulic fracturing processes. 25 Preliminary studies have been conducted for determine the mechanical properties of black slag steel mill before and after treatment according to the method described by the present invention. BR / AZAC / A220428-00 These studies have shown that black slag be able to withstand high pressure environments, making it suitable for use as a proppant. Further studies have been positively conducted 5 to determine the compressive strength of the black steelworks slag. Advantageously, another important aspect What was revealed by the studies was the fact that the amount of fine particles produced by black slag is minimal. In 10 This way, the risk of blockage of the fractures during hydrocarbon extraction. In a preferred embodiment, the method according to the invention comprises the following phases: - phase of transformation of black slag into 15 inert aggregate; - crushing phase of the inert aggregate; - screening phase of the inert aggregate shattered. Following the aggregate screening phase 20 inert it is possible to use the obtained material, that is, the crushed and sifted inert aggregate, as proppant in hydraulic fracturing operations. Advantageously, before the phase of transformation of black slag into inert aggregate 25 the collection phase of the black slag takes place from steelmaking processes, for example from the iron and steel industry of steel. In the transformation phase of black slag into inert aggregate, the black slag is processed in a BR / AZAC / A220428-00 to be converted into an inert aggregate free of harmful elements and ready for industrial use. The resulting aggregate will be a material homogeneous and characterized by good mechanical properties 5 and chemical. Preferably, the transformation phase of the black slag in inert aggregate involves the presence of two sub-phases: - a sub-phase of purification of the black slag; 10 - a sub-phase for removing impurities. More in detail, in the purification sub-phases and impurity removal can be used procedures for the removal of residual impurities such as metals or other unwanted compounds. 15 Such proceedings may include proceedings such as magnetic separation and / or treatment thermal. In some particular embodiments of the method according to the invention, between the transformation phase and the 20 crushing stage, the inert aggregate can be stored or further processed depending on the needs and necessities. The crushing phase has the aim of reducing further the particle size 25 of the inert aggregate, ensuring a distribution uniform grain size. In the screening phase, preferably of the type mechanical, the particles of crushed inert aggregate They are classified according to their size. BR / AZAC / A220428-00 In other words, the product obtained in the phases previous ones are sifted or sifted with a special instrumentation having a mesh size default. 5 Advantageously, the mesh size for the proppant are chosen based on standards industrial, with typical ranges ranging from 6 / 12 mesh for larger particles up to 70 / 140 mesh for the finest particles. 10 More specifically, the size selection depends on the specific operational needs: more meshes large ones are suitable for larger fractures, while finer meshes are employed in formations rocky with narrow fractures. 15 In this phase it is ensured that the proppant has an optimal particle size distribution for the application in hydraulic fracturing. Advantageously, the method according to the This invention represents a significant 20 advancements in industrial applications sustainable, proposing an effective procedure for the reuse of black bark as a proppant in the hydraulic fracturing. In fact, the method described not only allows you to 25 valorize an abundant industrial by-product, but It also offers benefits in terms of mechanical resistance, reduction of fine particle production so as to ensure performance comparable to that of the traditional materials such as sand 30 silicea. BR / AZAC / A220428-00 Equally advantageously, the use of the black slag as an alternative to silica sand promotes a circular economy approach, reducing the need to extract natural resources does not 5 renewables while reducing the impact environmental related to waste disposal steelworkers (in this case black slag). Therefore, the adoption of this method allows to contribute substantially to improving the 10 environmental sustainability of the energy sector and optimize the use of available resources. From the description given, the following are clear: characteristics of the method for the treatment of black steel mill slag for use in 15 hydraulic fracturing, which is the subject of the invention, just as the advantages are clear. It is clear, finally, that numerous other variants can be made to the method in question, without for this reason, to go beyond the principles of novelty inherent in the idea 20 inventiveness, as it is clear that, in practice implementation of the invention, the materials, the shapes and the The dimensions of the details illustrated may be any depending on the needs and they will be able to be replaced with equivalent ones. 25 Where the characteristics and techniques mentioned in any claims are followed by signs of reference, such reference marks have been enclosed for the sole purpose of increasing intelligibility of the claims and, consequently, such signs of 30 reference have no limiting effect BR / AZAC / A220428-00 on the interpretation of each element identified in example title from such reference marks. Barzanò & Zanardo Roma SpA BR / AZAC / A220428-00

Claims

CLAIMS 1. A method for treating black steelworks slag for use in hydraulic fracturing, comprising the following steps: - a step for transforming the black slag into inert aggregate; - a step for crushing the inert aggregate; - a step for screening the crushed inert aggregate.

2. Method for treating black steelworks slag for use in hydraulic fracturing as claimed in claim 1, characterised in that, following said screening step, the product obtained is used as a proppant in hydraulic fracturing.

3. A method for treating black steelworks slag for use in hydraulic fracturing as claimed in claim 1, characterised in that, prior to said black slag transformation step, there is a black steelworks slag collection step.

4. A method for treating black steel mill slag for use in hydraulic fracturing as claimed in one or more of the preceding claims, characterized in that said black slag transformation step comprises the following sub-steps: - black slag purification sub-step; - impurity removal sub-step. - 10 BR / AZAC / A220428-00 Barzanò & Zanardo 5. A method for treating black steelworks slag for use in hydraulic fracturing as claimed in claim 4, characterised in that said sub-phases comprise magnetic separation and / or heat treatment processes.

6. Method for treating black steelworks slag for use in hydraulic fracturing as claimed in one or more of the preceding claims, characterised in that said screening step 10 involves mechanical screening with a predefined mesh.

7. Method for treating black steelworks slag for use in hydraulic fracturing as claimed in one or more of the preceding claims 15, characterised in that the screening step is carried out with a mesh having intervals between 6 / 12 mesh and 70 / 140 mesh.