Production process for preparing rock wool by using large electric melting furnace

Abstract

The invention belongs to the technical field of rock wool production, and particularly relates to a production process for preparing rock wool by using a large electric melting furnace. According to the production technology of the rock wool for the outer wall based on the large-scale electric melting furnace for the rock wool, the heat conductivity coefficient of the prepared rock wool board for the outer wall ranges from 0.033 W / (m.K) to 0.038 W / (m.K), the acidity coefficient ranges from 2.5 to 3.0, and the rock wool board has the excellent heat preservation characteristic and durability.

Description

Technical Field

[0001] The invention belongs to the technical field of rock wool production, and in particular relates to a production process and application of rock wool prepared by using a large electric melting furnace. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Rock wool products have been widely used in the world for a long time due to their excellent fire prevention, thermal insulation, sound absorption and noise reduction functions. Rock wool production generally uses high-quality basalt as the main raw material, and dolomite and other minerals to assist in improving the mechanical properties of rock wool products. Rock wool products of different specifications and uses are formed by melting the raw materials, centrifuging the melt, collecting the wool, stacking, solidifying and compacting.

[0004] Thermal conductivity and acidity coefficient are important indicators for measuring the thermal insulation and durability of rock wool products of different specifications. The iron content (measured as ferric oxide) in the composition of rock wool products affects the melting point of the product. The higher the iron oxide content, the higher the melting point of the product. In addition, the thermal insulation performance and mechanical properties-tensile strength of rock wool products are also affected by the speed of the centrifuge, the cotton collector, and the pleating ratio parameter settings during the process.

[0005] Traditional rock wool production uses a cupola melting process, which involves the rock wool production process, including cupola melting, centrifugation, cotton collection, and solidification molding. The changes in process parameters at each stage, such as material melting temperature, high-speed centrifugal speed, cotton collection speed, pleating ratio parameter range, and equipment structure, affect the quality of the output rock wool to varying degrees. The electric melting furnace is easy to operate, stable in operation, and has small fluctuations in the flow and temperature of the melt. The electric melting furnace has obvious advantages in saving energy, reducing emissions, improving production efficiency, and utilizing solid waste and liquid waste. Therefore, seeking a production process for preparing rock wool using a large electric melting furnace can not only save resources and reduce carbon emissions, but also improve the thermal insulation properties and durability of rock wool. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a production process for preparing rock wool using a large electric melting furnace, which uses a large-size electric melting furnace to melt the raw materials, and then passes through a high-speed centrifuge, a cotton collector, a pleating machine and a curing device to form rock wool products. The thermal conductivity of the prepared rock wool is between 0.033 and 0.038 W / (m·K), and the acidity coefficient ranges from 2.5 to 3.0, with excellent thermal insulation properties and durability.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] In a first aspect, the present invention provides a production process for preparing rock wool using a large electric melting furnace, comprising the following steps:

[0009] S1. Use basalt, dolomite and industrial waste as raw materials and adopt large electric melting furnace melting process to obtain high temperature melt;

[0010] S2, the high-temperature melt enters a four-roll centrifuge, undergoes centrifugal fiber formation to form cotton fibers, and is simultaneously combined with an auxiliary coolant to obtain a fiber mixture after cooling;

[0011] S3. The fiber mixture is collected by a cotton collector to obtain a rock wool primary felt, which is then stacked by a pendulum, formed and weighed, cured and formed, and cut to obtain rock wool.

[0012] The industrial waste includes but is not limited to fly ash, coal-fired slag, manganese slag, ferroalloy slag, alumina red mud, magnesium slag and other non-ferrous metal ash, blast furnace slag, blast furnace dry slag, fly ash, and construction waste; the industrial waste is granular or powdered material with a particle size of less than or equal to 4 cm;

[0013] Wherein, the raw materials include, by weight: 15 to 70 parts of basalt, 5 to 15 parts of dolomite, and 20 to 80 parts of industrial waste.

[0014] Furthermore, in step S1, the large electric melting furnace melting process is specifically as follows:

[0015] The raw materials enter the large electric melting furnace through the screw conveyor and the feeding pipe;

[0016] Large electric melting furnaces use a hanging large vertical cylinder to lift the electrode. The electrode insertion depth is adjusted through the combined operation of the upper brake and the lower brake. The input power is controlled by the output voltage of the transformer connected to the electrode. The electrode pole center circle is set as an adjustable mechanism, and the pole center circle diameter is adjusted by the top screw pull rod.

[0017] The resistance heating effect of the electrode is used to generate high temperature to melt solid or powder raw materials. After the raw materials are completely melted, the melt gate drive device controls the melt to flow out.

[0018] Furthermore, the large electric melting furnace is provided with 10 to 30 feeding pipes, which are arranged around each electrode, between two electrodes, and in the center of the furnace body, respectively, to fully consider the balance between feeding and melting;

[0019] Each feeding pipe is equipped with a cooling fan to supply air. The cooling fan cools the feeding pipe extending into the furnace and adjusts the flue gas temperature in the furnace.

[0020] A rotating material distribution device is arranged at the tail of the material discharge pipe. The main body of the rotating material distribution device is a cone, and propeller-shaped blades are welded on the surface of the cone. The propeller-shaped blades can rotate under the push and impact of the raw materials when discharging materials, so that the melting in the electric melting furnace is more uniform and sufficient, and the material layer is covered more evenly.

[0021] Furthermore, the electrode pole center circle of the large electric melting furnace is arranged as an adjustable mechanism, the pole center circle diameter can be adjusted within the range of 1.8 to 4 meters, and the electrode column hanging bracket of the hanging electrode system and the electrode seal on the electric furnace cover can be adjusted within the range of 1.8 to 4 meters accordingly.

[0022] Furthermore, the furnace cover plate includes an inner ring plate with an electrode hole and an outer ring plate located outside the inner ring plate. A furnace cover feeder is arranged at the connection between adjacent furnace cover plates, and electrode holes for the electrodes to pass through are arranged on the three inner ring plates of the furnace cover; an air-cooling cover plate is arranged at the adjustable pole center circle, and the air-cooling cover plate is provided with a labyrinth air duct; the air outlet of the air-cooling cover plate is arranged along the periphery of the electrode, and the gas is blown into the furnace body along the gap between the electrode and the electrode hole, forming an annular airflow that seals the flue gas to cool the electrode hole.

[0023] Furthermore, the bottom refractory material of the large electric melting furnace is installed with several thermocouples of different depths to ensure that the temperature of the high-temperature rock wool melt is controlled at 1650°C to 2000°C.

[0024] Furthermore, the high-temperature melt meets the following standards: melt temperature ≥ 1600°C, relative viscosity 2-10 Pa·s, and acidity coefficient 2.5-3.0.

[0025] Furthermore, the speeds of the four-roll centrifuge are: 1st roller: 6800-7800 rpm, 2nd roller speed: 8000-8800 rpm, 3rd roller: 8200-9000 rpm, 4th roller: 8500-9500 rpm; the auxiliary coolant includes water, a hydrophobic agent and a binder, the hydrophobic agent is SHP-50, and the binder is a phenolic resin; preferably, in parts by mass, the auxiliary coolant contains: 80-90 parts of water, 10-20 parts of binder, and 1-2 parts of hydrophobic agent; further preferably, the auxiliary coolant contains: 85 parts of water, 13 parts of binder, and 2 parts of hydrophobic agent.

[0026] Furthermore, the cotton collector has a rotation speed of 150-180 m / min.

[0027] In a second aspect, the present invention provides rock wool prepared by the production process described in the first aspect, wherein the thermal conductivity of the rock wool is 0.033-0.038 W / (m·K), the acidity coefficient is 2.5-3.0, the fiber melting point is 1100-1250°C, and the tensile strength is >20 KPa.

[0028] The present invention heats raw materials based on a large electric melting furnace. One of the innovations of the large electric melting furnace structure is that it provides a suitable cooling scheme. The furnace bottom is cooled by a plurality of independent furnace bottom air ducts to realize flexible control of local temperatures at different positions of the furnace bottom. The middle part of the furnace shell includes a cooling wall, and each layer of the cooling wall is divided into a plurality of independent blocks. Each cooling wall is an independent closed forced water-cooled closed circulation structure. The upper and lower ends of the bottom layer of the furnace shell are respectively connected to the middle part of the furnace shell and the furnace bottom. The bottom layer of the furnace shell includes an annular steel plate, and furnace bottom refractory materials are arranged inside the annular steel plate and inside the cooling wall in the middle part of the furnace shell. The furnace bottom refractory materials are installed with a plurality of thermocouples for monitoring the temperature changes of the furnace bottom refractory materials.

[0029] The innovation of the present invention also lies in that the electric melting furnace includes an adjustable pole center circle, the adjustable pole center circle is distributed in an equilateral triangle, the electrode is arranged on the adjustable pole center circle, and the three pieces are respectively arranged on the three inner ring plates at the innermost end of the furnace cover, and the relative distance from the center of the furnace cover is adjusted by a top screw pull rod; a fixed plate facing the center of the furnace cover is arranged on the furnace cover, and waist-shaped electrode holes for the electrodes to pass through are arranged on the three inner ring plates at the innermost end of the furnace cover, and a pair of limit blocks are respectively arranged on both sides of the waist-shaped electrode holes, and the limit blocks serve as tracks to limit the trajectory of electrode movement.

[0030] The present invention adjusts the electrode insertion depth through the electrode lifting device and adjusts the relative distance of the electrodes through the top wire pull rod with adjustable pole center circle, so that the material in the furnace is melted and the temperature reaches a predetermined temperature and is stable.

[0031] The beneficial effects of the present invention are as follows:

[0032] The present invention utilizes a large-sized electric melting furnace to melt the raw materials, matches and sets the process parameters, so that the fibers in the finished rock wool product are arranged in different ways, forming overlaps and bites in all directions, so that the finished product has good thermal insulation and mechanical properties. The thermal conductivity of the prepared rock wool board for exterior walls is between 0.033 and 0.038 W / (m·K), the acidity coefficient ranges from 2.5 to 3.0, and it has excellent thermal insulation properties and durability.

[0033] The electric melting furnace production process of the present invention can effectively utilize industrial waste. The electric furnace has a strong melting capacity, which can avoid the occurrence of powder crusting in the furnace, effectively increase the types and range of available industrial waste, and use industrial waste to replace natural resources as raw materials for preparing rock wool, thereby reducing the consumption of natural resources such as basalt and dolomite, saving resources and reducing carbon emissions. It is a more green and low-carbon production technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0035] Figure 1This is the process flow chart of rock wool production;

[0036] Figure 2 This is the front view of a large electric melting furnace for rock wool;

[0037] Figure 3 It is a schematic diagram of the material feeding system;

[0038] Figure 4 It is a schematic diagram of the electrode column, seal, and adjustable polar center circle structure;

[0039] Figure 5 This is a schematic diagram of the furnace cover structure;

[0040] Figure 6 Schematic diagram of the arc-shaped cooling wall structure in the middle of the furnace shell; wherein, (a) is a schematic diagram of a single arc-shaped cooling wall from a side view, and (b) is a schematic diagram of a single arc-shaped cooling wall from a top view.

[0041] In the figure: 1 furnace bottom; 1-1 furnace bottom fan; 1-2 furnace bottom air duct; 1-3 furnace bottom foundation; 1-4 furnace bottom support; 2 furnace shell bottom; 2-1 annular steel plate; 2-2 furnace shell bottom flange; 2-3 reinforcing ribs; 2-4 floor plate; 2-5 thermocouple; 3 furnace shell middle; 3-1 labyrinth water channel baffle; 3-2 inspection hole; 3-3 cooling wall outer plate; 3-4 cooling wall inner plate; 3-5 cooling water inlet and outlet; 3-6 cleaning door flange; 3-7 exhaust hole; 3- 8 Temperature detection hole; 3-9 Arc cooling wall; 4 Upper part of furnace shell; 4-1 Air inlet and outlet of upper part of furnace shell; 4-2 Monitoring hole; 4-3 Monitoring equipment; 4-4 Inspection hole of upper part of furnace shell; 4-5 Inspection door; 5 Furnace cover; 5-1 Air inlet and outlet of furnace cover; 5-2 Electrode hole; 5-3 Furnace cover feeding hole; 5-4 Furnace cover exhaust gas outlet; 5-5 Liquid level measuring hole; 5-6 Insulation material; 5-7 Expansion joint; 6 Melt outlet; 6-6 Melt outlet eye opening machine; 7 Iron outlet; 7 -3 plugging machine; 7-4 refractory channel; 7-5 ladle; 8 emergency exit; 9 unloading system; 9-1 kiln head storage bin; 9-2 electric screw conveyor; 9-3 weighing device; 9-4 flap valve; 9-5 unloading pipe; 9-6 cooling fan; 9-7 rotating material distribution device; 9-7-1 cone; 9-7-2 propeller-shaped blades; 9-7-3 driving power; 10 electrode system; 10-1 electrode; 10-2 electrode lifting device; 10-2-1 hanging Hanging vertical cylinder; 10-2-2 pressure release platform; 10-3 pressure release device; 10-3-1 upper brake; 10-3-2 lifting and lowering pressure release cylinder; 10-3-3 lower brake; 10-4 pressure ring; 11 adjustable pole center circle; 11-1 pole center circle air cooling cover plate; 11-2 pole center circle refractory material; 11-3 pole center circle air inlet; 11-4 fixing plate; 11-5 top screw pull rod; 11-6 limit block; 12 electrode seal; 12-1 clamping bolt; 12-2 clamping buckle. DETAILED DESCRIPTION

[0042] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0043] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0044] The present invention provides a production process for preparing rock wool by using an electric melting furnace, and its purpose is to solve how to use the electric melting furnace to prepare rock wool products with excellent thermal insulation properties and durability. Through tempering, melting, homogenization, fiberization and other aspects of control, rock wool products that meet the national product standards of GB / T19686-2015 rock wool insulation products for buildings or GB / T25975-2018 rock wool products for external insulation of building exterior walls are obtained. Compared with the traditional rock wool production method, the acidity coefficient is improved, and the chemical stability, high temperature resistance and water resistance of the product are also improved. In addition, the present invention adopts an electric melting furnace to prepare rock wool, which has great promotion value in the market, can replace the traditional production process for preparing rock wool, and use industrial waste instead of natural resources as raw materials for preparing rock wool, thereby reducing the consumption of natural resources basalt and dolomite, saving resources and reducing carbon emissions. It is a more green and low-carbon production technology.

[0045] Combination Figure 1 As shown, the present invention provides a production process for preparing rock wool using a large electric melting furnace, comprising the following steps:

[0046] S1. Use basalt, dolomite and industrial waste as raw materials and adopt large electric melting furnace melting process to obtain high temperature rock wool melt;

[0047] Specifically, raw materials are continuously circulated and supplied into the furnace shell through the feeding system of the electric melting furnace, and the raw materials rotate into the interior of the electric melting furnace through the feeding pipe.

[0048] The electric melting furnace of the present invention has a furnace diameter of 6-12 meters, a furnace height of 3-6 meters, an electrode diameter of 450-850 mm, an adjustable pole center circle diameter of 1.8-4.0 meters, a melting capacity of 10-30 tons / hour, and a power of 10-30 MVA.

[0049] Combination Figure 2-6As shown, the electric melting furnace of the present invention includes a furnace bottom 1, a furnace shell bottom layer 2, a furnace shell middle part 3, a furnace shell upper part 4, a furnace cover 5, a melt outlet 6, an iron discharge port 7, an emergency outlet 8, a material discharge system 9, an electrode system 10, an adjustable pole center circle 11 and an electrode seal 12.

[0050] The furnace bottom 1 is a frame supporting the upper structure, including a furnace bottom foundation 1-3 at the bottom and a furnace bottom support 1-4 located on the top of the furnace bottom foundation 1-3. The furnace bottom foundation 1-3 is connected to the furnace shell bottom layer 2 through the furnace bottom support 1-4. A furnace bottom air duct 1-2 is arranged above the furnace bottom foundation 1-3 and between the furnace bottom supports 1-4, and a furnace bottom fan 1-1 is arranged at the end of the furnace bottom air duct 1-2; the furnace shell bottom layer 2 includes an annular steel plate 2-1, reinforcing ribs 2-3 are arranged on the annular steel plate 2-1, and furnace bottom refractory materials are arranged inside the annular steel plate and inside the cooling wall in the middle of the furnace shell; the furnace bottom refractory materials are installed with several thermocouples for monitoring the temperature changes of the furnace bottom refractory materials. The electric melting furnace adopts refractory materials as the lining structure, wherein the refractory materials are a combination of high temperature and corrosion resistant refractory materials, mainly high aluminum, high magnesium and high chromium refractory materials.

[0051] The bottom of the furnace shell bottom layer 2 is connected to the furnace bottom 1 through the bottom plate 2-4, and the top is connected to the furnace shell middle part 3 through the furnace shell bottom flange 2-2; the furnace shell middle part 3 is composed of an arc-shaped cooling stave 3-9, which is connected to the furnace shell upper part 4 and the furnace shell bottom layer 2 through upper and lower flanges respectively, and connected to other cooling staves through side flanges. Triangular reinforcing ribs are set at the connection between the cooling stave inner plate 3-4, the cooling stave outer plate 3-3 and the upper and lower flanges and the side flanges to enhance the connection strength; the furnace shell upper part 4 includes an arc-shaped cooling stave, which is air-cooled or water-cooled. The furnace cover plate is divided into an inner ring plate with an electrode hole and an outer ring plate located outside the inner ring plate; a furnace cover discharge hole 5-3 is set at the connection between adjacent furnace cover plates, a furnace cover exhaust gas outlet 5-4 is set on one furnace cover plate, and a furnace cover liquid level measuring hole 5-5 is set on another furnace cover plate. An electrode system 10 is set on the furnace cover, including an electrode 10-1, an electrode lifting device 10-2, a pressing device 10-3, and a pressure ring 10-4. The bottom end of the electrode 10-1 extends into the furnace, at a position slightly above the middle part 4 of the furnace shell; the electrode lifting device 10-2 includes a hanging vertical cylinder 10-2-1 and a pressing platform 10-2-2, one end of the pressing platform 10-2-2 is connected to the hanging vertical cylinder 10-2-1, and the other end is connected to the pressing device 10-3. The electrode lifting device 10-2 is used to change the depth of the electrode 10-1 inserted into the charge, and adjust the operating resistance through the transformer connected to the electrode so that the power input into the furnace reaches the rated requirement. The three-phase electrodes are insulated from each other by high-temperature resistant insulating materials 5-6 between each furnace cover plate near the electrode 10-1 to ensure safety and avoid the formation of circular induced current due to electromagnetic induction. Expansion gaps are left between adjacent furnace cover plates to allow differential expansion between the plates.

[0052] The electrode system 10 is composed of an electrode 10-1, an electrode lift 10-2, a hanging vertical cylinder 10-2-1, a pressure release platform 10-2-2, a pressure release device 10-3, an upper brake 10-3-1, a lifting and lowering pressure release cylinder 10-3-2, a lower brake 10-3-3, and a pressure ring 10-4; each phase electrode 10-1 is composed of a set of upper brake 10-3-1, lower brake 10-3-3, and a pressure ring 10-4, and a lifting and lowering pressure release cylinder 10-3-2 is arranged between the upper brake 10-3-1 and the lower brake 10-3-3. The hanging vertical cylinder 10-2-1 is used to lift and lower the electrode 10-1, and the combined operation of the upper brake 10-3-1 and the lower brake 10-3-3 realizes the pressure release of the electrode 10-1. The opening, raising and releasing of the brake are all completed by the hydraulic system. In normal working state, the pressure of the butterfly spring group in the brake acts on the brake shoe to clamp the electrode body.

[0053] An electrode seal 12 is arranged at the contact position between the adjustable pole center circle 11 and the electrode 10-1. The electrode seal 12 adopts at least two levels of soft seals. Each level of soft seals is composed of multiple layers of high temperature resistant insulating materials. The high temperature resistant insulating materials are nested with each other. Each level adopts a clamping bolt 12-1 and a clamping buckle 12-2 to adjust the clamping. It has the advantages of strong self-adaptation ability and high reliability, so that the electrode sealing device can adapt to the vibration, deflection and slippage of the electrode during operation.

[0054] The furnace cover plate comprises an inner ring plate with electrode holes and an outer ring plate located outside the inner ring plate. A furnace cover blanking is arranged at the connection between adjacent furnace cover plates. Electrode holes for electrodes to pass through are arranged on the three inner ring plates of the furnace cover.

[0055] The three adjustable pole center circles are distributed in an equilateral triangle and are respectively arranged on the three inner ring plates at the innermost end of the furnace cover. The relative distance from the center of the furnace cover is adjusted by a top screw pull rod 11-5. A fixed plate 11-4 facing the center of the furnace cover is arranged on the furnace cover, and electrode holes for the electrodes to pass through are arranged on the three inner ring plates of the furnace cover. A pair of limit blocks 11-6 are also arranged on both sides of the electrode holes. The limit blocks serve as tracks to limit the trajectory of electrode movement.

[0056] The limit blocks 11-6 of the furnace cover 5 are located on both sides of the adjustable polar center circle 11, and the top screw rod 11-5 connects the furnace cover plate and the adjustable polar center circle 11. The top screw rod 11-5 is a threaded structure and is fixed on the fixed plate 11-4 by a nut. When the polar center circle diameter needs to be adjusted, the nut on the top screw rod 11-5 is turned, and the air-cooled cover plate 11-1 and the electrode seal 12 are pulled / pushed to slide along the limit blocks 11-6 to adjust the electrode position. When adjusting, the adjustable polar center circle 11 and the hanging vertical cylinder 10-2-1 can be adjusted at the same time. The controller is not involved here, and manual adjustment is adopted. Because the electromagnetic induction of the electric melting furnace here is strong, it is not suitable for an electric structure here.

[0057] A feeding system 9 is arranged above the furnace cover 5, comprising a kiln head storage bin 9-1, an electric screw conveyor 9-2, a weighing device 9-3, a flap valve 9-4, and a feeding pipe 9-5 which are connected in sequence. The feeding pipe 9-5 passes through the furnace cover 5, and a rotating feeding device 9-7 is arranged at the bottom of the feeding pipe 9-5; the electric melting furnace also comprises a melt outlet and a furnace door, the melt outlet 6 is arranged on a melt outlet base, the melt outlet base is a hollow water-cooled part connected to the cooling wall in the middle of the furnace shell, a water-cooled back plate is arranged on the back, and the melt outlet is controlled to open and close by a melt control door; an iron discharge port 7 is also arranged on the side wall of the middle 3 of the furnace shell, the iron discharge port 7 is provided with an eye opening and plugging machine 7-3, and a melt outlet eye opening machine 6-6 facing the melt outlet is also arranged; the liquid iron discharged from the iron discharge port 7 flows out through a refractory channel 7-4, and the refractory channel 7-4 sends the molten iron to a ladle 7-5 on the ground layer for collection, and at least 3 ladles are required, which are arranged in series from high to low. Two emergency exits 8 are also arranged on the side wall of the middle part 3 of the furnace shell, which are arranged on the side and bottom of the furnace shell respectively.

[0058] The electric melting furnace production process of the present invention can effectively utilize industrial waste, including but not limited to coal-fired slag, manganese slag, ferroalloy slag, alumina red mud, magnesium slag and other non-ferrous metal ash, blast furnace slag, blast furnace dry slag, fly ash, construction waste (building bricks, concrete, rock wool, slag wool, glass wool, aluminum silicate, etc.), etc. After proportioning, various waste materials and other raw materials can be used as long as the average content of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, iron oxide, titanium dioxide, etc. is within the range of rock wool or slag wool.

[0059] In some embodiments of the present invention, the composition of rock wool or slag wool after industrial waste is mixed with other raw materials is: 30-55% silicon dioxide, 10-20% aluminum oxide, 15-30% calcium oxide, 5-20% magnesium oxide, 0-15% iron oxide, and 0-5% titanium dioxide.

[0060] The basalt and dolomite described in the present invention are commercially available products, and their specific compositions and contents are shown in Table 1:

[0061] Table 1 Specific composition and content of basalt and dolomite

[0062] Raw material name <![CDATA[SiO 2 %]]> <![CDATA[Al 2 THE 3 %]]> CaO% MgO% <![CDATA[Fe 2 THE 3 %]]> <![CDATA[TiO 2 %]]> Basalt 46.8 15.5 8.5 8.0 11.0 2.0 dolomite 2.0 1.0 30.0 20.0 0.2 0.5

[0063] In some embodiments of the present invention, the basalt has a block size of 100-300 mm, an oversize ratio of <10%, an acidity coefficient of >1.2, and a density greater than 1.6 g / cm 3 The dolomite has a block size of 60-90 mm, and the proportion of super-sized particles is less than 10%.

[0064] The industrial waste of the present invention can be granules or powders, as long as the particle size after crushing is less than or equal to 4 cm. The strong melting capacity of the electric melting furnace avoids the problem of powders entering the furnace and forming crusts, effectively increasing the types and range of industrial wastes that can be used.

[0065] It takes 2 to 15 hours for the raw materials to melt and flow out from the discharge port. After a long period of high temperature process, various crystals in the raw materials have fully become a high-temperature liquid mixture of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, iron oxide and titanium dioxide.

[0066] Combination Figure 3 As shown, a material discharging system is arranged above the furnace cover of the present invention, including a kiln head storage bin, an electric screw conveyor, a weighing device, a flap valve, and a material discharging pipe which are connected in sequence. The material discharging pipe passes through the furnace cover, and a rotating material distributing device is arranged at the bottom.

[0067] The material unloading system 9 uses 8-16 kiln head storage bins, each of which is set to a storage capacity of 15-30 tons, which can ensure the usage for no less than 12 hours; the bottom of the kiln head storage bin is wear-resistant, and each kiln head storage bin corresponds to 1-2 unloading systems 9, and the unloading systems 9 have a total of 10-30 routes. The quantitative unloading uses an electric screw conveyor, and the speed and time of the electric screw conveyor are set to control the unloading amount. The electric screw conveyor is provided with a weighing device, and a flap valve is installed on the weighing device to accurately control the unloading demand according to the needs in the furnace.

[0068] The unloading system of the electric melting furnace is provided with 10 to 30 unloading pipes, which are arranged around each electrode, between two electrodes and in the center of the furnace body, respectively, to fully consider the balance between unloading and melting; the unloading pipe is made of non-magnetic stainless steel, and each unloading pipe is provided with a cooling fan 9-6 to supply air, which cools the unloading pipe extending into the furnace and adjusts the flue gas temperature in the furnace; a rotating feeding device is provided at the tail of the unloading pipe, and the main body of the rotating feeding device is a cone 9-7-1, and propeller-shaped blades 9-7-2 are welded on the surface of the cone; the cone and the propeller-shaped blades are both made of high-temperature resistant and wear-resistant materials, and the cone plays a guiding role. The propeller-shaped blades can rotate under the push and impact of the raw materials when unloading, and can also be rotated by an external driving power 9-7-3, so that the melting in the electric melting furnace is more uniform and sufficient, and the material layer is covered more evenly. The uniform material layer coverage is for the black top operation in the furnace. In the black top operation, the feeding layer on the top of the melt can buffer the influence of power changes on the melt temperature. The temperature of the blacktop operating free space and furnace cover does not exceed 500°C, heat loss is minimized, and the process exhaust gas and dust treatment is simpler, safer and more reliable.

[0069] The feeding pipe is equipped with a cooling fan to supply air, which reduces the temperature inside the furnace, lowers the ambient temperature for the generation of nitrogen oxides, reduces nitrogen oxide emissions, and no longer requires subsequent combustion of natural gas to heat up for SCR denitration reaction. The exhaust temperature inside the traditional rock wool furnace is high, at 600-800℃, and the concentration of nitrogen oxides is 300mg / m 3 The temperature of the flue gas in the furnace needs to be lowered to 200°C for dust collection and then raised to 300°C for SCR denitration reaction. The present invention reduces the flue gas temperature in the furnace by ventilating the feed pipe 9-5 position, controls the temperature to below 450°C, and reduces the total amount of nitrogen oxides produced by 50% year-on-year. After the flue gas is dusted, it does not need to undergo denitration reaction and can be directly discharged to meet the emission standards, reducing the use of natural gas.

[0070] After the raw materials enter the electric melting furnace, they are melted by adjusting the electrode insertion depth and controlling the input power. The bottom refractory material of the electric melting furnace is equipped with several thermocouples of different depths to detect the temperature and ensure that the output high-temperature rock wool melt temperature is controlled at 1650℃~2000℃.

[0071] The electric melting furnace cover of the present invention is provided with an electrode system, and a hanging large vertical cylinder is used to realize the lifting and lowering of the electrode, and the combined operation of the upper brake and the lower brake realizes the pressing and releasing of the electrode. The opening, raising and pressing and releasing of the brake are all completed by the hydraulic system. In the normal working state, the pressure of the butterfly spring group in the brake acts on the brake shoe to clamp the electrode body.

[0072] The diameter of the adjustable pole center circle 11 can be adjusted within the range of 1.8-4 meters, and the electrode column hanging bracket of the electrode system and the electrode seal on the electric furnace cover can be adjusted within the range of 1.8-4 meters accordingly.

[0073] The limit blocks of the furnace cover are located on both sides of the adjustable pole center circle. The top screw pull rod connects the furnace cover plate and the adjustable pole center circle. The top screw pull rod is a threaded structure and is fixed to the fixed plate by a nut. When the pole center circle diameter needs to be adjusted, the nut on the top screw pull rod is turned, and the air-cooled cover plate and the electrode seal are pulled / pushed to slide along the limit blocks to adjust the electrode position.

[0074] The setting of adjustable pole center circle can avoid the dead zone of melting in the furnace, accurately control the electrode resistance, improve the homogenization of the melt, improve the uniformity of power distribution, and improve the intensity of melt convection. The pole center circle is adjusted to change the electrode resistance distribution according to the process requirements such as electrode insertion depth, melt liquid level height, component formula, etc., so as to achieve balanced power, improve efficiency and increase output of large-sized electric melting furnaces.

[0075] The temperature is adjusted by air cooling of the furnace cover and furnace bottom and water cooling structure in the middle of the furnace shell, and the outflow of the high-temperature melt after melting is controlled by the melt door drive device.

[0076] Combination Figure 2-6As shown, the bottom 1 of the electric melting furnace is cooled by 6-20 independent air ducts 1-2, and each air duct 1-2 corresponds to a fan 1-1 to cool the bottom plate of the furnace shell. The area in the middle of the electric melting furnace that needs to be cooled is large and the temperature is high, while the area on both sides that need to be cooled is small and the temperature is low. Each channel uses an independent cooling fan to cool the bottom 1 of the furnace, and the air volume of any fan can be flexibly adjusted, so that the local temperature control of different parts of the bottom 1 of the furnace is more flexible.

[0077] The bottom layer 2 of the furnace shell is composed of an annular steel plate with a thickness of 20-30 mm, which is divided into 8-20 independent pieces and is located at the insulation of the furnace bottom 1. The bottom layer 2 of the furnace shell is connected by flanges 2-2 at the top and bottom. There are several holes on each upper flange 2-2, which is connected to the adjacent cooling wall by bolts and other fasteners. Reinforcement ribs 2-3 are also arranged between the flange 2-2 and the outer plate to strengthen the rigidity of the flange and the steel plate. The bottom plate is made of 20-30 mm thick steel plate. The bottom and top sheets are designed as a single piece, and the bottom plate 2-4 is made into 3-5 pieces or more for easy transportation and installation; the furnace bottom refractory is set inside the annular steel plate and inside the cooling wall in the middle of the furnace shell; the furnace bottom refractory is installed with several thermocouples 2-5 of different depths to monitor the temperature changes of the furnace bottom refractory.

[0078] The middle part of the furnace shell is composed of an arc-shaped cooling stave 3-9, each layer of the arc-shaped cooling stave is divided into 8-20 independent blocks, which are convenient for manufacturing, transportation and installation. Each independent closed forced water-cooled closed cycle includes a cooling stave inner plate 3-4, a cooling stave outer plate 3-3 and a cooling stave side plate. The cooling stave inner plate 3-4, the cooling stave outer plate 3-3 and the cooling stave side plate form a cavity, and a labyrinth waterway baffle 3-1 is arranged inside the cavity to set the water-cooled closed cycle into a labyrinth waterway form. Each arc-shaped forced cooling stave is provided with an inspection hole 3-2, a cooling water inlet and outlet 3-5, a cleaning door flange 3-6, an exhaust hole 3-7 and a temperature detection hole 3-8, and is connected to the upper part of the furnace shell and the bottom layer of the furnace shell through upper and lower flanges, and is connected to other cooling staves through side flanges. A triangular reinforcing rib is arranged at the connection between the cooling stave inner plate 3-4, the cooling stave outer plate 3-3 and the upper and lower flanges and the side flange to enhance the connection strength. The labyrinth is not limited to the up and down direction, and can also be left and right when necessary. The water channel flow cross-sectional area, water flow rate and water inlet temperature are strictly calculated based on the three-dimensional model Fluent finite element heat transfer simulation. This method can fully reduce the temperature of the inner wall refractory material, making it easier to slag inside the refractory material, forming a condensation furnace lining, and extending the service life of the refractory material.

[0079] The outer plate of the arc-shaped cooling stave is made of 5-10mm thick steel plate. The inner plate is made of 20-30mm thick steel plate. Considering the unfavorable conditions of thermal expansion and contraction in the furnace, the inner plate is set to be manufactured as a whole plate to avoid cracking. Each arc-shaped cooling stave is provided with 2 cooling water inlets and outlets, which are diagonally distributed; the upper part of each cooling stave is provided with an exhaust hole for discharging trapped air, and there are multiple exhaust holes according to the layout of the maze; the lower part of each cooling stave is also provided with multiple cleaning doors for cleaning accumulated impurities, rust, etc., and the cleaning door flange is sealed. The arc-shaped cooling stave is surrounded by flanges with dozens of holes on the flanges. The cooling stave is connected to the adjacent upper, lower, left and right cooling staves by bolts and other fasteners. Triangular reinforcement ribs are also provided between the flange and the outer plate to strengthen the rigidity of the flange.

[0080] The arc-shaped cooling wall is a forced closed-circulation water-cooling structure. The water pump provides water flow power. The forced closed-circulation water-cooling structure effectively reduces the temperature of the refractory materials in the furnace. The refractory materials are heat-conductive refractory materials. The forced closed-circulation water-cooling structure is to ensure that the inner wall of the electric furnace is slag-formed to form a condensed furnace lining. The slag layer is used to protect the refractory materials in the furnace and reduce the erosion of the refractory materials by the melt in the furnace. 5-20 temperature measuring points are set on each cooling wall. The temperature measuring points are evenly distributed at equal heights, and thermocouples and thermal resistors are used for temperature measurement. The temperature measuring points measure the change in the temperature of the cooling water in the water channel, and can also measure the temperature of the contact surface between the inner plate of the cooling wall and the refractory materials, the temperature of the contact surface between the outermost layer of refractory materials and the penultimate layer of refractory materials, and the temperature of the contact surfaces between other different layers of refractory materials. The measured temperature data are analyzed centrally, and combined with the electric valves and flow meters installed in the water cooling branches, the different flow rates of water entering different cooling walls are adjusted according to the changes in the temperature of the side walls of the furnace body, so as to achieve precise temperature control and prevent excessive water from causing the local furnace body temperature to be too low, resulting in excessive slag on the furnace wall and excessive heat loss; or insufficient water from causing the local furnace body temperature to be too high, causing erosion of the furnace wall refractory materials.

[0081] like Figure 2 As shown, the upper part 4 of the furnace shell is also composed of an arc-shaped cooling stave. Each layer of the arc-shaped cooling stave is divided into 8-20 independent blocks. The unique feature is that each block has an independent closed air-cooled closed cycle. The air-cooled closed cycle is arranged in a maze form. The maze is not limited to the up and down direction, but can also be left and right. The cross-sectional area, flow rate, and temperature of the air duct flow are calculated according to the three-dimensional model Fluent finite element heat transfer simulation, which can fully reduce the temperature of the refractory material on the surface of the insulation layer. The upper part 4 of the furnace shell is not limited to air cooling, but can also be water-cooled. The air cooling is for the comprehensive utilization of the heat of the outlet hot air. On the outer plate of the cooling stave, each arc-shaped cooling stave module is respectively provided with an upper furnace shell air inlet and outlet 4-1, which is divided into an independent air inlet and an air outlet.

[0082] The upper part 4 of the furnace shell has 3-8 monitoring holes 4-2 on the side for monitoring the furnace conditions. The monitoring holes 4-2 are equipped with monitoring equipment 4-3. The monitoring equipment 4-3 is resistant to high temperatures and has other cooling structures such as water cooling and air cooling. The purpose of monitoring is to monitor the electrodes, magma, raw material distribution, and melting state in the furnace in real time to evaluate the production status. At the same time, 3-5 upper furnace shell inspection holes 4-4 are opened on the side, and inspection doors 4-5 are installed. The inspection doors are sealed and have refractory materials inside. The upper part 4 of the furnace shell has expansion gaps between adjacent plates to allow differential expansion between the plates.

[0083] like Figure 4 As shown, the furnace cover 5 is divided into independent 6-20 block structures, and the furnace cover 5 is provided with a furnace cover air inlet and outlet 5-1, an electrode hole 5-2, a material discharge hole 5-3, a furnace cover exhaust gas outlet 5-4, and a liquid level measuring hole 5-5; the three phases are insulated from each other by high temperature resistant insulating materials 5-6 between each furnace cover near the electrode to ensure safety and avoid the formation of a circular induced current due to electromagnetic induction; the furnace cover 5 has expansion joints 5-7 between adjacent plates to allow differential expansion between the plates.

[0084] The furnace cover adopts an air-cooled structure, and the flow channel is composed of baffles, which form a maze with a constant cross-sectional area to make the wind speed passing through it as constant as possible. This ensures the cooling of the equipment and its service life. Each block adopts an independent wind system, and the air volume is adjustable through a valve. This structure can avoid the adverse effects of accidental water leakage into the furnace caused by the traditional water-cooled furnace cover structure while ensuring cooling. Air cooling can also make comprehensive use of the heat of the outlet hot air.

[0085] The adjustable polar center circle is located at the adjustable polar center circle of the furnace cover, and is provided with a polar center circle air cooling cover plate 11-1. A polar center circle refractory material 11-2 is provided under the polar center circle air cooling cover plate 11-1 for protection. The polar center circle air cooling cover plate 11-2 is provided with a labyrinth air duct and a polar center circle air inlet 11-3 for air cooling. The air inlet volume can be adjusted. The choice of air cooling is to ensure cooling while avoiding the adverse effects of accidental water leakage in the traditional water-cooled furnace cover structure. The air outlet of the polar center circle air cooling cover plate 11-1 is arranged along the periphery of the electrode, and the gas is blown into the furnace body along the gap between the electrode and the electrode hole, forming a ring airflow that seals the flue gas. On the one hand, it effectively cools the electrode hole of the furnace cover, and on the other hand, it cools the connection position of the electrode and the adjustable polar center circle, while guiding the air flow line in the electric melting furnace to avoid the overflow of flue gas in the electric melting furnace.

[0086] The return air heat from the upper part of the furnace shell and the air-cooled furnace cover can be used in the dryer to dry the raw materials, thus realizing full utilization of the heat. The cooling of the upper part of the furnace shell and the furnace cover of the traditional rock wool electric furnace is basically external water cooling. The external water circulation takes away part of the heat while cooling the electric furnace. At the same time, the external water circulation requires a cooling tower for cooling, which is actually just energy conversion, resulting in heat waste in the water circulation. The upper part of the furnace shell and the furnace cover of the rock wool electric furnace invented in this invention are cooled by an air-cooled structure. Natural air is blown into the furnace cover through a fan for cooling, taking away heat and increasing the outlet air temperature. The return air with heat enters the dryer combustion chamber through a pipe, thereby increasing the heat supply and reducing the use of natural gas.

[0087] Combination Figure 1-Figure 6 In the above electric melting furnace melting process, first of all, it is necessary to ensure the uniform melting of the raw materials, achieve a stable melt composition, and set the temperature of the outflowing high-temperature melt to provide a stable melt for the next fiber forming process. The specific process is as follows:

[0088] S1. Add the mixed raw materials into the electric melting furnace, turn on the power to heat the electric melting furnace, adjust the electrode insertion depth through the electrode lifting device, and adjust the relative distance of the electrodes through the top wire pull rod of the adjustable pole center circle, so that the materials in the furnace are melted and the temperature reaches the predetermined temperature and is stable; the power of the electric melting furnace is adjusted mainly through the temperature monitoring results of the melt, and the furnace temperature of the electric melting furnace is monitored by an inserted thermocouple, and the test is performed every 1 to 2 hours. At the same time, the temperature of the electric melting furnace is regulated by adjusting the air cooling of the furnace cover and the bottom of the furnace and the water cooling structure in the middle of the furnace shell to ensure that the melt temperature in the electric melting furnace is between 1650°C and 2000°C. After all the raw materials are melted and the melt is homogenized, the high-temperature melt is controlled to flow out through the melt door drive device, wherein the standard bars of the high-temperature melt are as follows: melt temperature ≥ 1600°C, relative viscosity is 2 to 10Pa·s, and acidity coefficient is 2.5 to 3.0;

[0089] S2, the high-temperature rock wool melt enters the four-roll centrifuge, and is centrifugally fiberized to form cotton fibers, which are then synchronously combined with the auxiliary coolant by matching the corresponding four-roll centrifuge speed to obtain a fiber mixture after cooling;

[0090] The high-temperature melt prepared by the electric melting furnace melting process is discharged to the four-roll centrifuge, and the high-temperature melt flows to the four-roll centrifuge through the slag chute. The centrifugal speed of the four-roll centrifuge is controlled as follows: 1 roller: 6800-7800 rpm, 2 roller speed: 8000-8800 rpm, 3 roller: 8200-9000 rpm, 4 roller: 8500-9500 rpm; the method of gradually increasing the speed can make the fiber separation time longer, and at the same time, the force of fiber centrifugation will also increase, so that the layer distribution of the fiber will be more delicate, and the cotton yield will increase accordingly. The high-temperature melt is centrifugally fiberized by the four-roll centrifuge. Due to the action of gravity, the cotton fiber is separated from the slag ball in the four-roll centrifuge, and is cooled and formed under the action of a high-speed blower to form cotton fiber, and an auxiliary coolant is sprayed on the rock wool fiber simultaneously, wherein the auxiliary coolant components are: 85 parts of water, 13 parts of a binder, and 2 parts of a hydrophobic agent.

[0091] S3. The fiber mixture is collected by a cotton collector to obtain a rock wool primary felt, which is matched with the corresponding cotton collector speed. After pendulum cotton stacking, shaping and weighing, curing and shaping, and cutting, the rock wool is obtained.

[0092] Negative pressure adsorption is used to collect cotton fibers sprayed with binders on the conveyor belt of the cotton collector to form a primary rock wool felt. The felt is then stacked by a pendulum, formed and weighed, and solidified (pressed by rollers and dried at high temperature) to form a secondary felt. The binder is solidified with the cotton fibers in a high temperature environment. The rock wool is then cut (such as longitudinally or cross-cut), stacked, and packaged to form qualified rock wool.

[0093] The rock wool prepared by the electric melting furnace process has performance that meets the standard GBT19686-2015 rock wool insulation products for construction. The thermal conductivity of the rock wool board is between 0.033 and 0.038 W / (m·K), and the acidity coefficient ranges from 2.5 to 3.0, and has excellent thermal insulation properties and durability.

[0094] The production process of preparing rock wool by using an electric melting furnace of the present invention is further introduced below in conjunction with the embodiments.

[0095] Example 1: Production process of rock wool using an electric melting furnace

[0096] (1) Raw material components: by weight: 17 parts of basalt, 8 parts of dolomite, and 75 parts of industrial waste.

[0097] Among them, the block size of basalt is 100-300mm, the proportion of super-granularity is less than 10%, the acidity coefficient is greater than 1.2, and the density is greater than 1.6g / cm 3The size of dolomite is 60-90mm, the proportion of super-sized particles is less than 10%, and the particle size of industrial waste is ≤4cm; the composition of basalt and dolomite is shown in Table 1, and slag is used as industrial waste, with the following specific composition: silicon dioxide 40%, aluminum oxide 18%, calcium oxide 16%, magnesium oxide 3.8%, iron oxide 7.8%, and titanium dioxide 1%.

[0098] (2) An electric melting furnace is used to melt the raw materials. The raw materials are conveyed to the electric melting furnace through a screw conveying system. The power of the electric melting furnace is adjusted mainly by monitoring the temperature of the melt. The temperature of the electric melting furnace is monitored by an inserted thermocouple every 1 to 2 hours. At the same time, the electric melting furnace cooling device is used to control the temperature to ensure that the temperature of the electric melting furnace is stable at 1650°C to 2000°C. After all the raw materials are melted and the melt is homogenized, the temperature and viscosity of the melt are tested to meet the standards. The mixed melt is then controlled by a melt door drive device to flow out the high-temperature melt. The standards for the melt are as follows: melt temperature ≥ 1600°C, relative viscosity 2 to 10 Pa·s, and acidity coefficient 2.5 to 3.0.

[0099] (3) Centrifugal process: The high-temperature melt passes through the chute and the ultra-high-speed centrifuge rollers, combines with the auxiliary coolant, and is cooled to obtain a fiber mixture, which goes to the cotton collection process;

[0100] (4) Cotton collection process: The speed of the cotton collector is adjusted, and the fiber mixture is collected by the cotton collector to obtain a primary felt, which is then sent to the pleating process. After the pendulum cotton stacking, shaping and weighing, curing and shaping, and cutting, the rock wool is obtained.

[0101] Among them, the pleating process and the curing process (pendulum folding, forming and weighing, curing and forming, and cutting) are carried out according to conventional methods and process parameters.

[0102] Embodiment 2-5

[0103] The raw materials and process flow are the same as those in Example 1. The melt temperature after melting, the centrifuge speed, and the cotton collector speed are shown in Table 2.

[0104] Table 2 Melt outflow temperature, centrifuge speed, cotton collector speed settings

[0105]

[0106] Comparative Examples 1-3

[0107] The raw materials and process flow are the same as those in Example 1. The melt temperature after melting, the centrifuge speed, and the cotton collector speed are shown in Table 3.

[0108] Table 3 Melt outflow temperature, centrifuge speed, cotton collector speed settings

[0109]

[0110] According to the above embodiments and comparative examples, the performance parameters of the corresponding rock wool products are obtained through comprehensive testing:

[0111] Table 4 Performance parameters of rock wool products

[0112]

[0113]

[0114] Through the analysis of the embodiments and comparative examples, it is concluded that the melt temperature of the raw materials output by high-temperature melting in a large-size electric melting furnace is in the range of 1650-1800°C. Under the matching four-roll centrifuge speed, cotton collector speed and different pleating ratio system process parameter conditions, high-performance rock wool board products are obtained, with a thermal conductivity of 0.033-0.038W / (m·K), an acidity coefficient in the range of 2.5-3.0, an iron content of about 7.0-9.5%, a fiber melting point of 1100-1250°C, good durability, and a tensile strength (taking 140kg / m3 board as an example) greater than 20KPa.

[0115] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A production process for preparing rock wool using a large electric melting furnace, characterized in that: The following steps are involved: S1. Use basalt, dolomite and industrial waste as raw materials and adopt large electric melting furnace melting process to obtain high temperature melt; S2, the high-temperature melt enters a four-roll centrifuge, undergoes centrifugal fiber formation to form cotton fibers, and is simultaneously combined with an auxiliary coolant to obtain a fiber mixture after cooling; S3, the fiber mixture is collected by a cotton collector to obtain a rock wool primary felt, and the rock wool is obtained after being stacked by a pendulum, formed and weighed, cured and formed, and cut; The industrial waste includes but is not limited to fly ash, coal-fired slag, manganese slag, ferroalloy slag, alumina red mud, magnesium slag and other non-ferrous metal ash, blast furnace slag, blast furnace dry slag, fly ash, and construction waste; The industrial waste is in the form of granules or powders, with a particle size of less than or equal to 4 cm; Wherein, the raw materials include, by weight: 15-70 parts of basalt, 5-15 parts of dolomite, and 20-80 parts of industrial waste.

2. The production process for preparing rock wool using a large electric melting furnace as claimed in claim 1, characterized in that: In step S1, the large electric melting furnace melting process is specifically as follows: The raw materials enter the large electric melting furnace through the screw conveyor and the feeding pipe; Large electric melting furnaces use a hanging large vertical cylinder to lift the electrode. The electrode insertion depth is adjusted through the combined operation of the upper brake and the lower brake. The input power is controlled by the output voltage of the transformer connected to the electrode. The electrode pole center circle is set as an adjustable mechanism, and the pole center circle diameter is adjusted by the top screw pull rod. The resistance heating effect of the electrode is used to generate high temperature to melt solid or powder raw materials. After the raw materials are completely melted, the melt gate drive device controls the melt to flow out.

3. The production process for preparing rock wool using a large electric melting furnace as claimed in claim 2, characterized in that: The large electric melting furnace is provided with 10 to 30 feeding pipes, which are arranged around each electrode, between two electrodes, and in the center of the furnace body, respectively, to fully consider the balance between feeding and melting; Each feeding pipe is equipped with a cooling fan to supply air. The cooling fan cools the feeding pipe extending into the furnace and adjusts the flue gas temperature in the furnace. A rotating material distribution device is arranged at the tail of the material discharging pipe. The main body of the rotating material distribution device is a cone, and propeller-shaped blades are welded on the surface of the cone. When the material is discharged, the propeller-shaped blades can rotate under the push and impact of the raw materials, so that the melting in the electric melting furnace is uniform and sufficient, and the material layer is evenly covered.

4. The production process for preparing rock wool using a large electric melting furnace as claimed in claim 2, characterized in that: The electrode center circle of the large electric melting furnace is arranged as an adjustable mechanism, and the diameter of the electrode center circle can be adjusted within the range of 1.8 to 4 meters.

5. The production process for preparing rock wool using a large electric melting furnace as claimed in claim 4, characterized in that: The furnace cover plate comprises an inner ring plate with an electrode hole and an outer ring plate located outside the inner ring plate. A furnace cover blanking is arranged at the connection between adjacent furnace cover plates. Electrode holes for the electrodes to pass through are arranged on the three inner ring plates of the furnace cover. An air cooling cover is provided at the adjustable pole center circle, and a labyrinth air duct is provided on the air cooling cover; the air outlet of the air cooling cover is arranged along the periphery of the electrode, and the gas is blown into the furnace body along the gap between the electrode and the electrode hole, forming an annular airflow that seals the flue gas and cools the electrode hole.

6. The production process for preparing rock wool using a large electric melting furnace as claimed in claim 2, characterized in that: The bottom refractory material of the large electric melting furnace is equipped with several thermocouples to ensure that the temperature of the high-temperature rock wool melt is controlled at 1650°C to 2000°C.

7. The production process for preparing rock wool using a large electric melting furnace as claimed in claim 2, characterized in that: The high-temperature melt meeting the standards is as follows: melt temperature ≥ 1600°C, relative viscosity 2 to 10 Pa·s, and acidity coefficient 2.5 to 3.

0.

8. The production process for preparing rock wool using a large electric melting furnace as claimed in claim 1, characterized in that: The speeds of the four-roll centrifuge are: 1st roller: 6800-7800 rpm, 2nd roller speed: 8000-8800 rpm, 3rd roller: 8200-9000 rpm, 4th roller: 8500-9500 rpm; the auxiliary coolant includes water, a hydrophobic agent and a binder, the hydrophobic agent is SHP-50, and the binder is a phenolic resin; preferably, in parts by mass, the auxiliary coolant contains: 80-90 parts of water, 10-20 parts of binder, and 1-2 parts of hydrophobic agent; further preferably, the auxiliary coolant contains: 85 parts of water, 13 parts of binder, and 2 parts of hydrophobic agent.

9. The production process for preparing rock wool using a large electric melting furnace as claimed in claim 1, characterized in that: The speed of the cotton collector is 150-180 m / min.

10. A rock wool obtained by the production process of preparing rock wool using a large electric melting furnace according to any one of claims 1 to 8, characterized in that: The thermal conductivity of the rock wool is 0.033-0.038 W / (m·K), the acidity coefficient is 2.5-3.0, the fiber melting point is 1100-1250° C., and the tensile strength is greater than 20 KPa.

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