CN111116225A

CN111116225A - Microporous light sintered brick and preparation method thereof

Info

Publication number: CN111116225A
Application number: CN202010107248.3A
Authority: CN
Inventors: 张岩斌
Original assignee: Xi'an Meike Power Technology Co ltd
Current assignee: Xi'an Meike Power Technology Co ltd
Priority date: 2019-03-14
Filing date: 2020-02-21
Publication date: 2020-05-08

Abstract

The invention relates to a microporous light sintered brick and a preparation method thereof. The microporous light sintered brick raw material consists of tailings and a pore-forming agent; the pore-forming agent is at least one of straw powder, sawdust and polystyrene; the raw materials comprise the following components in percentage by mass: 85-95% of tailings and 5-15% of pore-forming agent; the tailings are directly obtained after the coal slime is separated by separation equipment, and the mass percentages of the components in the tailings are as follows: SiO 2₂45-65% of Al₂O₃18 to 25% of Fe₂O₃3-5% of CaO, 3-5% of MgO, and the balance of other elements; the plasticity index of the tailings is 11-18, and the heat value is 1.6-2.5 MJ/kg. The performance of the microporous light sintered brickMeets or even exceeds the national standard, and realizes the reutilization of the coal slime tailings. The preparation method has simple process and greatly saves time cost.

Description

Microporous light sintered brick and preparation method thereof

Technical Field

The invention belongs to the field of production of wall materials, and particularly relates to a microporous light sintered brick and a preparation method thereof.

Background

At present, shale, fly ash and coal gangue are mixed with sludge, waste residue, sawdust and straw as pore-forming agents to carry out micropore transformation on the traditional brick, so that the porosity of the sintered brick is improved, the distribution of the internal pore diameter of a product is improved, and the functions of energy conservation, environmental protection, light weight, sound insulation, heat preservation and the like are realized. Although the shale is adopted as the main material, the cultivated land is saved, and the vegetation and the ecological environment are still damaged when the raw materials are exploited. The fly ash and the coal gangue are used as main materials, and the brick body has heavy mass, frost, black core, lime burst, weak weathering resistance and low compressive strength. Although the hollow brick has the advantages of light weight, heat preservation and insulation functions, the hollow brick has large cavity, thin inner wall and low compressive strength. Therefore, the development of a new raw material with good quality is the key to avoid the defects of the sintered light microporous bricks.

The raw coal input amount is about 24 hundred million tons every year in China, and the total coal slime amount generated is 2-3 hundred million tons. Because the coal slime is composed of kaolin, argillaceous shale, polystyrene, coal and other minerals, and is subjected to multiple times of flotation, soaking, stirring and filter pressing, the coal and the slime are mutually adsorbed and completely argillized and are difficult to utilize. At present, part of coal slime is used for power generation of a power plant, and part of coal slime is recycled by repeatedly adopting the existing equipment and process, so that part of coal is recycled by all methods, but the heat value of tailings is still 7-8 MJ/kg. The tailings are used for power generation in a power plant, and the calorific value is too low to be directly utilized; the open air stacking pollutes the environment, and the in-situ landfill wastes resources; if the sintered brick is prepared, a large amount of heat value is still contained, the heat value is many times higher than the brick making requirement, the shrinkage rate is large when the sintered brick is sintered at 1150 ℃, the stockpiling height can be deformed during sintering, the brick body collapses, and the microporous light sintered brick meeting the national standard performance cannot be obtained. In the prior art, coal slime tailings contain larger heat value, so that the coal slime tailings are all used as additives for preparing microporous light sintered bricks, and even if the coal slime tailings are used as main materials, shale, fly ash or other substances with lower heat value are still required to be added in large proportion. Therefore, a large amount of coal slime still exists and cannot be utilized.

Therefore, how to effectively utilize a large amount of coal slime to reduce energy waste and environmental pollution and prepare the microporous lightweight sintered brick meeting the national standard performance becomes a problem to be solved urgently.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides the microporous light sintered brick, which takes tailings as a main raw material and is matched with a pore-forming agent, so that the effective utilization of coal slime tailings is realized, and the energy waste is reduced. The tailings are matched with a pore-forming agent to sinter the high-quality microporous light sintered brick in full internal heat, so that the energy is saved, the performance of the brick meets or even exceeds the national standard, and the reutilization of the coal slime tailings is realized. Specifically, the technical scheme of the invention is as follows:

the microporous light sintered brick comprises the raw materials of tailings and a pore-forming agent; the pore-forming agent is at least one of straw powder, sawdust and polystyrene; the mass percentage range of the tailings is 85-95%, and the mass percentage range of the pore-forming agent is 5-15%; the tailings are directly obtained after the coal slime is separated by separation equipment, and the mass percentage ranges of the components in the tailings are as follows: SiO 2₂45-65% of Al₂O₃18 to 25% of Fe₂O₃3-5% of CaO, 3-5% of MgO, and the balance of other elements; the plasticity index range of the tailings is 11-18, and the heat value range is 1.6-2.5 MJ/kg; the loss on ignition range of the tailing pore-forming agent after proportioning is 6-10%.

Further, the tailing component is 90%, and the pore-forming agent is 10%.

Further, the tailings comprise the following components in percentage by mass: SiO 2₂55% of Al₂O₃20% of Fe₂O₃4% of CaO, 4% of MgO and the balance of other elements; the plasticity index of the tailings is 15, and the heat value is 2.0 MJ/kg; the loss on ignition of the tailing after being matched with the pore-forming agent is 8 percent.

Further, the water content of the tailings is within a range of 22-25%.

Further, the sorting apparatus is a sorting column comprising a primary sorting cylinder (100) and at least two secondary sorting cylinders (101, 102) in series communication with the primary sorting cylinder (100), the main separation column (100) and the secondary separation columns (101, 102) respectively comprise an ore pulp multipoint distributor (7) arranged at the upper middle position in the main separation column, a high-speed dispersing device (2) arranged outside the main separation column and communicated with the ore pulp multipoint distributor (7) through a pipeline, a foam collecting device (4) arranged at the top of the main separation column, an atomizing and spraying device (5) arranged on the foam collecting device (4), a plurality of micro-bubble generators (10) arranged around the outer wall of the lower part of the foam collecting device, an air conveying pipe (9) arranged outside the main separation column in a surrounding manner and communicated with the micro-bubble generators (10) through a pipeline, and a tailing overflow discharge pipe (11) arranged outside the main separation column and communicated with the bottom of the main; the high-speed dispersion machine (2) comprises a motor (22) arranged outside the high-speed dispersion machine and a dispersion rotor (23) connected with the motor (22) and arranged inside the high-speed dispersion machine; the pipeline of the tailing overflow discharge pipe (11) and the high-speed disperser device (2) is provided with an adjusting valve (111); the air conveying pipe (9) is sequentially connected with the air storage tank (8) and the air compressor (81) through pipelines; a pressure stabilizing valve and an air flow regulating valve are arranged on the air storage tank (8); the main separation cylinder (100) also comprises an ore pulp reaction box (1) and a feeding port (103) which are arranged outside the main separation cylinder and are sequentially communicated with the high-speed dispersion machine device (2) through pipelines; a material conveying pump (3) is arranged on a pipeline in front of the ore pulp multi-point distributor (7); the medicine adding port (61) and the medicine supplementing port (62) are communicated with the medicine chest (6) through pipelines; the ore pulp reaction box (1) comprises a stirring rotating sheet (112) and a dropping plate (113) which are arranged in the ore pulp reaction box (1); a chemical adding port (61) is arranged on a pipeline between the ore pulp reaction box (1) and the feeding port (103); the tailings overflow discharge pipe (11) of the main separation column body (100) is communicated with the high-speed disperser device (2) of the secondary separation column body (101) which is connected in sequence through a pipeline, the tailings overflow discharge pipe (11) of the secondary separation column body (101) is communicated with the high-speed disperser device (2) of the secondary separation column body (102) which is connected in sequence through a pipeline, and the tailings overflow discharge pipe (11) and the pipeline of the high-speed disperser device (2) are both provided with a medicine supplementing opening (62); a discharge outlet (105) is arranged on the tailing overflow discharge pipe (11) of the last secondary separation cylinder (102) which is connected in sequence; the foam trapping devices (4) of the main separation cylinder (100) and the secondary separation cylinders (101, 102) which are communicated in sequence are communicated through a pipeline, and a discharge hole (104) is arranged on the pipeline.

Further, the preparation method of the microporous light sintered brick adopts full internal heat sintering and comprises the following steps:

step 1: drying the tailings until the water content is 15-18%;

step 2: placing the prepared pore-forming agent into a material box of an automatic feeder, wherein the granularity is less than 0.1 mm;

and step 3: mixing the tailings and the pore-forming agent in proportion, conveying the mixture to a stirring system, stirring and rolling;

and 4, step 4: inputting the solid obtained in the step 3 into a vacuum extruder for extrusion, an automatic strip cutting machine for strip cutting, and a blank cutting machine for block cutting in sequence to obtain a brick blank block;

and 5: preliminarily drying the green brick blocks;

step 6: and (3) putting the green bricks into a tunnel kiln according to the flow, and sequentially drying, preheating and roasting to obtain the microporous light sintered bricks.

Further, the stirring system in the step 3 is composed of a first stirring system and a second stirring system which are connected in sequence; the stirring speed range of the first stirring system is 100-300 r/min; the stirring speed of the second stirring system is 300-600 r/min; the stirring time is from feeding to natural discharging.

Furthermore, the stirring speed range of the first stirring system is 200-220 r/min; the stirring speed of the second stirring system is 450-480 r/min.

Further, in the step 4, the extrusion pressure range of the extruder is 3-10MPa, preferably 4.00MPa, and the vacuum degree range is 0.07-0.09 MPa.

Further, the extrusion pressure of the extruder in step 4 was 4.00 MPa.

Further, the preliminary drying in step 5 is preferably natural air drying or drying by using the residual heat of a tunnel kiln.

Further, in the step 6, the roasting temperature is 850-1050 ℃, and the roasting time is 40-48 hours. Compared with the prior art, the microporous light sintered brick and the preparation method thereof have the following advantages:

the invention relates to a microporous light sintered brick: (1) a large number of closed fine holes are formed in the microporous light sintered brick body, so that the thermal resistance of the brick body is increased to a certain extent, the purposes of heat preservation, heat insulation and noise reduction of the brick body are enhanced, and the heat preservation and heat insulation performance of the masonry wall body is improved; (2) the microporous light sintered brick has a large number of pores in the brick body, so that the quality of the brick body is reduced; (3) the microporous light sintering time is 32% faster, the yield is high, and the cost is low; (4) the raw material granularity of the microporous light sintered brick is less than 85 percent of 0.043MM, the microporous light sintered brick has fine granularity, high plasticity, good molding and beautiful appearance; (5) al of the microporous light sintered brick of the invention₂O₃Al is more than the raw material of the traditional baked brick₂O₃The thickness is 15-25%, and the product has the characteristics of high compression strength and breaking strength, freezing resistance, sound absorption, corrosion resistance, water permeability and air permeability; (6) the weight of the brick body is reduced by more than 35 percent compared with the traditional micropore sintering brick.

The preparation method of the microporous light sintered brick comprises the following steps: (1) the raw material coal slime is obtained after being sorted by the sorting column, so that the comprehensive utilization industrial chain of the coal slime is prolonged, seamless butt joint of upstream and downstream industrial chains is realized, and wastes are changed into valuables; (2) the microporous light sintered brick utilizes biological wastes such as straws and the like, reduces the pollution to the environment and solves the problem of straw recycling; (3) the microporous light sintered brick is sintered by full spontaneous combustion, the sintering speed is high, the yield is high, and the energy-saving and environment-friendly effects are achieved because combustible materials are not added; (4) compared with the traditional micropore baked brick, the method avoids building a raw material warehouse, a finished warehouse and the like. The investment is small, the occupied area is small, the process flow is simple, the production cost is low, the energy is saved, the environment is protected, and the method is suitable for industrial production; (5) compared with the traditional microporous sintered brick, the method has the advantages that the crushing and burdening processes, raw material conveying, civil engineering and the like are avoided, the production cost is reduced, and the energy is saved and the environment is protected; (6) the raw materials are directly fed into a brick making workshop from the coal slime tailings, so that the loading, unloading and transporting costs of the raw materials are reduced, and the pollution to the environment is reduced; (7) compared with the traditional micropore sintering brick, the brick making process is less, and the overall efficiency is improved by 30 percent.

Drawings

FIG. 1 is a schematic view of a sorting column according to the present invention.

The structures corresponding to the numbering in the figures are as follows:

1. a pulp reaction box; 2. a high-speed disperser apparatus; 3. a delivery pump; 4. a foam trapping device; 5. an atomizing spray device; 6. a medicine chest; 7. a pulp multi-point distributor; 8. a gas storage tank; 9. a gas delivery pipe; 10. the microbubble generator 11 is a tailing overflow discharge pipe; 22. a motor; 23. dispersing and rotating sheets; 61. a medicine adding port; 62. a medicine supplementing opening; 81. an air compressor; 100. a main sorting cylinder; 101. a secondary sorting column; 102. a secondary sorting column; 103. a feeding port; 104. a discharge port; 105. a discharge outlet; 111. adjusting a valve; 112. stirring and rotating the sheet; 113. a drop plate.

Detailed Description

The technical scheme of the invention is clearly and completely described in the following with reference to the accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. Other embodiments, which can be derived by one of ordinary skill in the art from the embodiments of the present invention without creative efforts, are within the scope of the present invention.

Selecting coal slime separated by the prior art, wherein the ash content percentage range of coking coal slime is 50-60%; the percentage of ash content of the power coal slime with the calorific value ranging from 8MJ/Kg to 12MJ/Kg ranges from 35% to 60%; the coal slime has a heat value of 8-16MJ/Kg and a water content of 20-30%; and crushing and pulping the coal slime through a coal slime pulping machine to obtain coal slime water. The coal slurry pulping machine can be used for pulping by adopting the coal slurry pulping machine disclosed by the Utility model of the research institute of Thangshan of the middleman chemical industry group (publication number: CN 206334764U). Carrying out coal slime classification on the coal slime water through a 120-mesh screen of a JKS type high-frequency coal slime dehydration sieve, and sorting the obtained coarse coal slime through a TBS interference bed; the obtained fine coal slime pulp with the grain diameter less than 0.125mm is floated by a flotation machine, and the tailings after flotation are input into separation equipment for separation to obtain the raw material tailings used by the invention.

The sorting device is an inflatable nanobubble sorting column, and referring to fig. 1, a main sorting column 100 is sequentially connected with two

secondary sorting columns

101 and 102;

the main separation column 100 and the

secondary separation columns

101 and 102 respectively comprise an ore pulp multipoint distributor 7 arranged at the middle-upper position in the main separation column, a high-speed dispersion machine device 2 arranged outside the main separation column and communicated with the ore pulp multipoint distributor 7 through a pipeline, a foam collecting device 4 arranged at the top of the main separation column, an atomization spraying device 5 arranged on the foam collecting device 4, a plurality of micro-bubble generators 10 arranged around the outer wall of the lower part of the main separation column, a conveying gas pipe 9 arranged around the outer part of the main separation column and communicated with the micro-bubble generators 10 through a pipeline, and a tailings overflow discharging pipe 11 arranged outside the main separation column and communicated with the bottom of the main separation column.

The gas delivery pipe 9 is connected with the gas storage tank 8 and the air compressor 81 in sequence through pipelines.

The pipeline in front of the ore pulp multi-point distributor 7 is provided with a material conveying pump 3 for conveying ore pulp at a high speed, and the conveying pump 3 conveys the ore pulp which is fused, emulsified and mineralized by the high-speed dispersion machine device 2 to the ore pulp multi-point distributor 7, so that the ore pulp spraying material is in an atomization form, the solid, liquid and medicine of the ore pulp are in full contact collision with floating bubbles, and a good separation effect is achieved.

The high-speed dispersion machine device 2 is a barrel body with the diameter of 400mm, and comprises a motor 22 and a dispersion rotor 23 connected with the motor 22 and arranged in the high-speed dispersion machine device; the motor 22 may be a dc motor or an ac motor; a model FSF-80 dispersion machine manufactured by Shanghai Banderrui industry Co., Ltd is adopted, a motor 22 directly drives a dispersion rotor 23 with the diameter of 300mm, and the rotating speed is 1460 r/min. The high-speed dispersion machine device 2 has a certain negative pressure due to the high-speed rotation of the dispersion rotor 23, and the centrifugal force is applied, so that ore pulp or foam concentrate is diffused outwards through the center of the disc surface and is in strong friction collision with the inner wall of the barrel body, and the shearing, dispersion, emulsification and defoaming effects on the foam ore pulp are formed. The dispersed and emulsified ore pulp is beneficial to secondary separation.

The main separation column 100 further comprises a pulp reaction box 1 and a feed inlet 103 arranged outside the main separation column and sequentially communicated with the high-speed disperser device 2 through pipelines. A dosing port 61 is arranged on a pipeline between the ore pulp reaction box 1 and the feeding port 103, the dosing port 61 is communicated with the medicine box 6 through a pipeline and is used for dosing operation, and the ore pulp reaction box 1 comprises a stirring rotating sheet 112 and a falling plate 113 which are arranged inside the ore pulp reaction box 1; under the impact of the ore pulp, the stirring rotating sheet 112 rotates to stir and mix the ore pulp, and then the ore pulp is impacted on the plurality of staggered falling plates 113 and is sequentially stirred and mixed again; so that the ore pulp is subjected to primary reaction, contact and fusion in the reaction box 1.

The tailing overflow discharge pipe 11 of the main separation column 100 is communicated with the high-speed disperser device 2 of the secondary separation column 101 which is connected in sequence through a pipeline, the tailing overflow discharge pipe 11 of the secondary separation column 101 is communicated with the high-speed disperser device 2 of the secondary separation column 102 which is connected in sequence through a pipeline, and the pipelines for connecting the ore overflow discharge pipe 11 at the tail of the main separation column 100 and the secondary separation column 101 with the high-speed disperser device 2 are provided with the medicine supplementing openings 62; a discharge outlet 105 is arranged on the tailing overflow discharge pipe 11 of the last secondary separation cylinder 102 which is connected in sequence; and a regulating valve 111 is arranged on a pipeline connecting the tailing overflow discharge pipe 11 and the high-speed dispersion machine device 2 and used for regulating the flow of tailings.

The medicine adding port 61 and the medicine supplementing port 62 are both communicated with the medicine box 6 through pipelines and are used for adding or supplementing medicines.

The froth trapping devices 4 of the primary sorting cylinder 100 and the

secondary sorting cylinders

101, 102 communicating in sequence communicate through a conduit and are provided with a discharge opening 104 on said conduit.

The gas conveying pipe 9 is used for communicating the microbubble generator 10; the micro-bubble generator 10 is arranged in a stepped double-layer mode, 16 micro-bubble generators are arranged on the upper layer, 8 micro-bubble generators are arranged on the lower layer, the inflatable nano-bubble generators on each layer are arranged around the column body in an equal ratio, the length is kept constant, bubbles are uniformly dispersed in the column body, the collision and adhesion probability of ore pulp and the bubbles is improved, and the ore dressing efficiency is improved. The microbubble generator 10 is an inflatable nanometer microbubble generator 10 which is manufactured by Shanghai Ding-based pneumatic machinery Limited and has the model number of DJ 101-700-0.25, when the pressure is 6-7 kpa, the diameter of the foamed foam is 0.0025mm, the foam is uniformly inflated and constant in size, the bubbles are slightly broken in ascending flow, and the foam is fully contacted, collided and mineralized with sunken ore pulp, and has good coal and mud analytic dissociation effect on tailings with the fine particle size of less than 0.045mm accounting for 95%.

The microbubble generator 10 directly sprays air into the main separation column 100 and the

secondary separation columns

101 and 102 to generate nano bubbles, and nano bubble groups slowly rise from the bottom of the columns; ore pulp is apart from about 1.2m department of top cylinder and is given into ore pulp multiple spot distributor 7 by delivery pump 3, the ore pulp downward flow, the bubble that rises collides at the district contact of collecting with the ore particle that descends countercurrent, accomplish the bubble mineralization, make the coal particle who is glutinous on the bubble come up the foam blanket, the foam blanket thickness sets up 1.2 meters, the mud ash that the desorption bubble carried under the effect of atomizing spray set 5 spray rinsing water, make the bubble that rises accomplish the secondary enrichment, the high-speed dispersion machine device 2 in foam entrapment device 4 is gone into to the concentrate foam overflow of enrichment, high-speed dispersion machine device 2 is sheared the foam, the dispersion, emulsification, the defoaming.

A pressure stabilizing valve and an air flow regulating valve are arranged on the air storage tank 8 and are used for regulating the gas suction amount of the micro-bubble generator 10; an air compressor 81 is used to input the gas into the gas storage tank 8 as a gas source.

The atomization spray device 5 is set in a general manifold form, a straight pipe is respectively arranged vertically and horizontally, a plurality of atomization spray heads are dispersedly arranged on the straight pipe, the atomization spray heads can be compression type spray heads, ultrasonic type spray heads or net type spray heads, and are preferably compression type, so that the stability is high; the traditional spray water device adopts a pipeline dripping or spraying mode, an atomizing nozzle is not installed, the contact surface of the sprayed water and foam is small and is less than 15% of a foam area, and therefore, the ash flushing effect of foam-carried lime is poor; the atomization nozzle is additionally arranged, so that the sprayed water can be atomized and dispersed on the foam, no dead angle exists, the foam area is fully covered by 100%, the problem of serious foam back ash is effectively solved, and the separation effect is improved; the atomized water is full of the foam area, the height of the atomization device is adjusted to avoid impacting the foam, the falling atomized water speed is reduced, and the using amount of the atomized water ranges from 60 m to 90m³H, about the feed quantity45-80% of the foam is beneficial to washing mud ash carried by the foam.

The coking coal pulp with the concentration of 70g/L, the ash content of 55% and the heat value of 8-12 MJ/kg is taken as an example.

Step 1: starting an automatic dosing device of a medicine box 6, configuring a collecting agent and a foaming agent according to the ratio of 1.2:1, and inputting the collecting agent and the foaming agent into the ore pulp reaction box 1 through a medicine adding port 61;

step 2: conveying ore pulp to the ore pulp reaction box 1 through the feeding port 103, driving the stirring rotating sheet 112 of the ore pulp reaction box 1 to run by the input ore pulp, and fusing and dropping the ore pulp through the dropping plate 113;

and step 3: starting a high-speed dispersion machine device 2 and a delivery pump 3 outside the main separation cylinder 100, wherein the rotating speed of a motor 22 is 1460r/min, the rotating speed of the delivery pump 3 is 1460r/min, and ore pulp is delivered to an ore pulp multipoint distributor 7 in the main separation cylinder 100 by the delivery pump 3 under the conditions of shearing, dispersion, emulsification and mineralization of a high-speed dispersion rotating sheet 23;

and 4, step 4: when the ore pulp is filled to 60% of the volume of the main separation column 100, starting an air compressor 81, adjusting the total gas transmission amount of a gas transmission tank 8, starting a micro-bubble generator 10 at the upper part 100 and the lower part 100 of the main separation column, setting the pressure to be 6-7 kpa, and setting the diameter of foaming foam to be 0.0025 mm;

and 5: when the foam collecting device 4 of the main separation cylinder 100 overflows foam, the atomization spraying device 5 of the main separation cylinder 100 is started, the foam product is discharged from the discharge hole 104, and coal with ash content below 20% and recovery rate above 35% can be obtained; at the moment, the ash content of the tailings can reach more than 72 percent and the heat value is below 4.2 MJ/kg;

step 6: opening a regulating valve 111 of the main sorting cylinder 100, and a high-speed disperser device 2 and a delivery pump 3 outside the secondary sorting cylinder 101, wherein the rotating speed of a motor 22 is 1460r/min, the rotating speed of the delivery pump 3 is 1460r/min, and opening an automatic medicine supplementing device of a medicine box 6; tailings are conveyed to an external high-speed disperser device 2 of the secondary separation column 101 through a tailing overflow discharge pipe 11 of the separation column 100, medicines are supplemented through a medicine supplementing opening 62 in front of the secondary separation column 101, and tailings are conveyed to an ore pulp multipoint distributor 7 in the secondary separation column 101 by a conveying pump 3 after ore pulp is sheared, dispersed and emulsified by a high-speed dispersion rotating sheet 23;

and 7: when the tailings fill 60% of the volume of the secondary separation column 101, starting the micro-bubble generator 10 of the secondary separation column 101, and setting the pressure at 6-7 kpa and the diameter of foaming foam at 0.0025 mm;

and 8: when foam overflows from the foam trapping device 4 of the secondary separation cylinder 101, the atomization spraying device 5 of the secondary separation cylinder 101 is started, the foam product is discharged from the discharge port 104, and coal with ash content below 20% can be obtained; at the moment, the ash content of the tailings can reach more than 78 percent and the heat value is below 2.5 MJ/kg;

and step 9: starting the regulating valve 111 of the secondary sorting cylinder 101, the high-speed disperser device 2 and the delivery pump 3 outside the secondary sorting cylinder 102, wherein the rotating speed of the motor 22 is 1460r/min, the rotating speed of the delivery pump 3 is 1460r/min, and starting the automatic medicine replenishing device of the medicine chest 6; tailings are conveyed to an external high-speed disperser device 2 of the secondary separation column 102 through a tailings overflow discharge pipe 11 of the separation column 101, medicines are supplemented through a medicine supplementing opening 62 in front of the secondary separation column 102, and tailings are conveyed to an ore pulp multipoint distributor 7 in the secondary separation column 102 by a conveying pump 3 after ore pulp is sheared, dispersed and emulsified by a high-speed dispersion rotating sheet 23;

step 10: when the tailings fill 60% of the volume of the secondary separation cylinder 102, starting the micro-bubble generator 10 on the secondary separation cylinder 102, and setting the pressure at 6-7 kpa and the diameter of foaming foam at 0.0025 mm;

step 11: when the foam collecting device 4 of the secondary separation cylinder 102 overflows foams, the atomization spraying device 5 of the secondary separation cylinder 102 is started, foam products are discharged from the discharge hole 104, and a small amount of coal with ash content below 20% can be obtained;

step 12: the tailings are discharged into a tailing pond through a discharge port 105 on a tailing overflow discharge pipe 11 of the secondary separation column 102 for concentration and filter pressing, and tailings with ash content of 78-85% and heat value of 1.6-2.5 MJ/kg can be obtained.

Taking power coal slurry with the concentration of 80g/L, the ash content of 50 percent and the heat value of 8-16MJ/kg as an example:

the same separation steps as the coking coal slime pulp are carried out, and tailings with ash content of 78-85% and heat value of 1.6-2.5 MJ/kg can be finally obtained.

The tailings are the raw material tailings of the invention: SiO 2₂45-65% of Al₂O₃18 to 25% of Fe₂O₃3-5% of CaO, 3-5% of MgO, and the balance of other elements, wherein the percentages are mass percentages; the plasticity range is 11-18; the heating value ranges from 1.6MJ/Kg to 2.5MJ/Kg, and the water content ranges from 22% to 25%. The loss on ignition range of the tailings and the pore-forming agent after proportioning is 6-10%. The shrinkage rate of the microporous light sintered brick prepared by the invention is not more than 1.6%.

The compressive strength, the apparent porosity and the like of the microporous light sintered brick prepared by the invention are tested and analyzed according to GB/T2542 and 2003 wall building brick experimental method and GB/T3810.3-2006 ceramic brick experimental method; the thermal conductivity of the test piece is tested according to GB/T10294-.

The heat conductivity coefficient of the microporous light sintered brick prepared by the invention is not more than 0.20-0.25W/(m.K) at normal temperature, so that the purpose of heat preservation and heat insulation of the reinforced material is achieved, the strength requirement in GB26538-2011 sintered heat-preservation brick and heat-preservation building block is met, the microporous light sintered brick can be used as a filler wall, and the use requirement of a bearing brick is met in strength.

Example 1

The microporous light sintered brick is prepared from tailings and a pore-forming agent. When the pore-forming agent is straw powder, the tailings account for 85% by mass and the pore-forming agent accounts for 15% by mass; the tailings are directly obtained by separating coal slime through a separation column, and the mass percentages of the components in the tailings are as follows: SiO 2₂45% of Al₂O₃25% of Fe₂O₃5% of CaO, 5% of MgO and the balance of other elements; the plasticity index of the tailings is 11, and the heat value is 1.6 MJ/kg. The granularity of the tailings is less than 0.1mm, and the granularity of the tailings is less than 0.043mm and accounts for 85 percent. The loss on ignition after the tailing is matched with the pore-forming agent is 10 percent.

The preparation method of the microporous light sintered brick comprises the following steps:

step 1: conveying tailings to a coal slime dryer to dry until the water content is 15-18%, wherein the coal slime dryer is a coal slime roller drying system;

step 2: crushing straws by using a vertical crusher, feeding the crushed straws into a ball mill to be processed into straw powder micro-particle fibers, and screening out the straw powder with the particle size of less than 0.1 mm;

and step 3: mixing the tailings and the straw powder in proportion, and sequentially conveying the mixture to a first stirring system and a second stirring system which are continuous and have the model number of SJJ280 multiplied by 36 for stirring and rolling; the stirring speed of the first stirring system is 100-300 r/min, preferably 200-220 r/min; the stirring speed of the second stirring system is 300-600 r/min, preferably 450-480 r/min; the stirring time is from feeding to natural discharging.

And 4, step 4: inputting the solid obtained in the step 3 into a vacuum extruder with the model number of JKY 50/50D-35 bipolar vacuum extruder for extrusion, a KQZ automatic slitter for slitting, a QP21 automatic slab cutter for slicing to obtain brick billets, and a billet mold: 240mmX115mmX57 mm; the extrusion pressure is 3-10MPa, preferably 4.00MPa, and the vacuum degree is 0.07-0.09 MPa.

And 5: setting 14 layers of blanks by a ZMP330 hydraulic automatic blank setting system, and naturally drying the blanks outdoors for 24 hours or drying the blanks by using the waste heat of a tunnel kiln;

step 6: the green bricks are put into a tunnel kiln according to the flow and are sequentially dried, preheated and roasted; the drying temperature range is 100-200 ℃, the preheating temperature range is 300-500 ℃, the roasting temperature control range is 850-1050 ℃, and the roasting time is 43 hours; and (4) taking the sintered bricks out of the kiln after being sequentially cooled to obtain the microporous light sintered bricks, wherein the sintering qualification rate is 98%.

The comprehensive water absorption rate of the prepared microporous light sintered brick reaches over 58 percent, the apparent porosity reaches over 57 percent, and the compressive strength is 7.3 MPa. A certain amount of micropores which are uniformly distributed are formed in the fired brick blank. The shrinkage rate of the microporous light sintered brick prepared by the invention is not more than 1.6%.

Example 2

The microporous light sintered brick is prepared from tailings and a pore-forming agent. When the pore-forming agent is sawdust, the mass percent of the tailings is 90%, and the mass percent of the sawdust is 10%; the tailings are directly obtained by separating coal slime through a separation column, and the mass percentages of the components in the tailings are as follows: SiO 2₂55% of Al₂O₃20% of Fe₂O₃4% of CaO, 4% of MgO and the balance of other elements; the plasticity index of the tailings is 15, and the heat value is 2.0 MJ/kg. The granularity of the tailings is less than 0.1mm, and the granularity of the tailings is less than 0.043mm and accounts for 85 percent. The loss on ignition of the tailing and the sawdust after being mixed is 8 percent.

step 2: grinding sawdust by a vertical grinder, feeding the sawdust into a ball mill to be processed into powder micro-particle fibers, and screening the sawdust to obtain sawdust with the particle size of less than 0.1 mm;

and step 3: mixing the tailings and the sawdust in proportion, and sequentially conveying the mixture to a first stirring system and a second stirring system which are continuous and have the model number of SJJ280 multiplied by 36 for stirring and rolling; the stirring speed range of the first stirring system is 100-300 r/min, preferably 200-220 r/min; the stirring speed range of the second stirring system is 300-600 r/min, preferably 450-480 r/min; the stirring time is from feeding to natural discharging.

step 6: the green bricks are put into a tunnel kiln according to the flow and are sequentially dried, preheated and roasted; the drying temperature range is 100-200 ℃, the preheating temperature range is 300-500 ℃, the roasting temperature is controlled at 850-1050 ℃, and the roasting time is 46 hours; and (4) taking the sintered bricks out of the kiln after being sequentially cooled to obtain the microporous light sintered bricks, wherein the sintering qualification rate is 98%.

The comprehensive water absorption rate of the prepared microporous light sintered brick reaches more than 46 percent, the apparent porosity reaches more than 42 percent, and the compressive strength is 8.9 MPa. A certain amount of micropores which are uniformly distributed are formed in the fired brick blank. The shrinkage rate of the microporous light sintered brick prepared by the invention is not more than 1.6%.

Example 3

The microporous light sintered brick is prepared from tailings and a pore-forming agent. When the pore-forming agent is polystyrene, the mass percent of the tailings is 95 percent, and the mass percent of the polystyrene is 5 percent; the tailings are directly obtained by separating coal slime through a separation column, and the mass percentages of the components in the tailings are as follows: SiO 2₂65% of Al₂O₃18% of Fe₂O₃3% of CaO, 3% of MgO and the balance of other elements; the plasticity index of the tailings is 18, and the heat value is 2.5 MJ/kg. The granularity of the tailings is less than 0.1mm, and the granularity of the tailings is less than 0.043mm and accounts for 85 percent. The loss on ignition of the tailing after being matched with polystyrene is 6 percent.

step 1: conveying the tailings to a coal slime dryer to dry until the water content is 15-18%, wherein the coal slime dryer is a coal slime roller drying system;

step 2: mixing the tailings and polystyrene in proportion, and sequentially conveying the mixture to a first stirring system and a second stirring system which are continuous and have the model number of SJJ280 multiplied by 36 for stirring and rolling; the stirring speed of the first stirring system is 100-300 r/min, preferably 200-220 r/min; the stirring speed of the second stirring system is 300-600 r/min, preferably 450-480 r/min; the stirring time is from feeding to natural discharging.

And step 3: inputting the solid obtained in the step 3 into a vacuum extruder with the model number of JKY 50/50D-35 bipolar vacuum extruder for extrusion, a KQZ automatic slitter for slitting, a QP21 automatic slab cutter for slicing to obtain brick billets, and a billet mold: 240mmX115mmX57 mm; the extrusion pressure range is 3-10MPa, preferably 4.00MPa, and the vacuum degree range is 0.07-0.09 MPa.

And 4, step 4: setting 14 layers of blanks by a ZMP330 hydraulic automatic blank setting system, and naturally drying the blanks outdoors for 24 hours or drying the blanks by using the waste heat of a tunnel kiln;

and 5: the green bricks are put into a tunnel kiln according to the flow and are sequentially dried, preheated and roasted; the drying temperature is 100-200 ℃, the preheating temperature is 300-500 ℃, the roasting temperature is controlled at 850-1050 ℃, and the roasting time is 48 hours; and (4) taking the sintered bricks out of the kiln after being sequentially cooled to obtain the microporous light sintered bricks, wherein the sintering qualification rate is 98%.

The comprehensive water absorption rate of the prepared microporous light sintered brick reaches more than 43 percent, the apparent porosity reaches more than 40 percent, and the compressive strength is 11.8 MPa. A certain amount of micropores which are uniformly distributed are formed in the fired brick blank. The shrinkage rate of the microporous light sintered brick prepared by the invention is not more than 1.6%.

The above embodiments are only for illustrating the technical solutions of the present invention, and not for limiting the same. The present invention is not limited to the precise arrangements described above and illustrated in the drawings, and it is not intended that the specific embodiments of the present invention be limited to the specific details set forth herein. Various changes and modifications to the invention, which will be apparent to those skilled in the art, can be made without departing from the spirit of the invention, and are intended to be within the scope of the invention.

Claims

1. A micropore light baked brick is characterized in that: the microporous light sintered brick raw material consists of tailings and a pore-forming agent; the pore-forming agent is at least one of straw powder, sawdust and polystyrene; the mass percentage range of the tailings is 85-95%, and the mass percentage range of the pore-forming agent is 5-15%; the tailings are directly obtained by separating coal slime through separation equipment, and the mass percentage ranges of the components in the tailings are as follows: SiO 2₂45-65% of Al₂O₃18 to 25% of Fe₂O₃3-5% of CaO, 3-5% of MgO, and the balance of other elements; the plasticity index range of the tailings is 11-18, and the heat value range is 1.6-2.5 MJ/kg; the loss on ignition range of the tailings and the pore-forming agent after proportioning is 6-10%.

2. The microporous lightweight sintered brick of claim 1, wherein: the tailing component is 90%, and the pore-forming agent is 10%.

3. The microporous lightweight sintered brick of claim 1, wherein: the tailings comprise the following components in percentage by mass: SiO 2₂55% of Al₂O₃20% of Fe₂O₃4% of CaO, 4% of MgO and the balance of other elements; the plasticity index of the tailings is 15, and the heat value is 2.0 MJ/kg; the loss on ignition of the tailings and the pore-forming agent after proportioning is 8%.

4. The microporous lightweight baked brick according to any one of claims 1 to 3, wherein: the water content range of the tailings is 22-25%.

5. The microporous lightweight sintered brick of claim 1, wherein: the sorting device is a sorting column which comprises a main sorting cylinder (100) and at least two secondary sorting cylinders (101, 102) which are communicated with the main sorting cylinder (100) in sequence, the main separation column (100) and the secondary separation columns (101, 102) respectively comprise an ore pulp multipoint distributor (7) arranged at the upper middle position in the main separation column, a high-speed dispersing device (2) arranged outside the main separation column and communicated with the ore pulp multipoint distributor (7) through a pipeline, a foam collecting device (4) arranged at the top of the main separation column, an atomizing and spraying device (5) arranged on the foam collecting device (4), a plurality of micro-bubble generators (10) arranged around the outer wall of the lower part of the foam collecting device, an air conveying pipe (9) arranged outside the main separation column in a surrounding manner and communicated with the micro-bubble generators (10) through a pipeline, and a tailing overflow discharge pipe (11) arranged outside the main separation column and communicated with the bottom of the main; the high-speed dispersion machine (2) comprises a motor (22) arranged outside the high-speed dispersion machine and a dispersion rotor (23) connected with the motor (22) and arranged inside the high-speed dispersion machine; the pipeline of the tailing overflow discharge pipe (11) and the high-speed disperser device (2) is provided with an adjusting valve (111); the air conveying pipe (9) is sequentially connected with the air storage tank (8) and the air compressor (81) through pipelines; a pressure stabilizing valve and an air flow regulating valve are arranged on the air storage tank (8); the main separation cylinder (100) also comprises an ore pulp reaction box (1) and a feeding port (103) which are arranged outside the main separation cylinder and are sequentially communicated with the high-speed dispersion machine device (2) through pipelines; a material conveying pump (3) is arranged on a pipeline in front of the ore pulp multi-point distributor (7); the medicine adding port (61) and the medicine supplementing port (62) are communicated with the medicine chest (6) through pipelines; the ore pulp reaction box (1) comprises a stirring rotating sheet (112) and a dropping plate (113) which are arranged in the ore pulp reaction box (1); a chemical adding port (61) is arranged on a pipeline between the ore pulp reaction box (1) and the feeding port (103); the tailings overflow discharge pipe (11) of the main separation column body (100) is communicated with the high-speed disperser device (2) of the secondary separation column body (101) which is connected in sequence through a pipeline, the tailings overflow discharge pipe (11) of the secondary separation column body (101) is communicated with the high-speed disperser device (2) of the secondary separation column body (102) which is connected in sequence through a pipeline, and the tailings overflow discharge pipe (11) and the pipeline of the high-speed disperser device (2) are both provided with a medicine supplementing opening (62); a discharge outlet (105) is arranged on the tailing overflow discharge pipe (11) of the last secondary separation cylinder (102) which is connected in sequence; the foam trapping devices (4) of the main separation cylinder (100) and the secondary separation cylinders (101, 102) which are communicated in sequence are communicated through a pipeline, and a discharge hole (104) is arranged on the pipeline.

6. The microporous lightweight sintered brick of claim 4, wherein: the preparation method of the microporous light sintered brick adopts full internal heat sintering and comprises the following steps:

step 1: drying the tailings until the water content is 15-18%;

and 5: preliminarily drying the green brick blocks;

7. The method for preparing a microporous lightweight sintered brick according to claim 6, wherein: the stirring system in the step 3 is composed of a first stirring system and a second stirring system which are connected in sequence; the stirring speed of the first stirring system is 100-300 r/min, preferably 200-220 r/min; the stirring speed of the second stirring system is 300-600 r/min, preferably 450-480 r/min; the stirring time is from feeding to natural discharging.

8. The method for preparing a microporous lightweight sintered brick according to claim 6, wherein: in the step 4, the extrusion pressure of the extruder is 3-10MPa, preferably 4.00MPa, and the vacuum degree is 0.07-0.09 MPa.

9. The method for producing a sintered brick according to claim 6, wherein: the primary drying in the step 5 is preferably natural air drying or drying by using the residual heat of a tunnel kiln.

10. The method for preparing a microporous lightweight sintered brick according to claim 6, wherein: in the step 6, the roasting temperature ranges from 850 ℃ to 1050 ℃, and the roasting time ranges from 40 hours to 48 hours.