阅读说明：本技术 一种难选硫酸烧渣梯级制备不同规格高性能选煤用重介质粉的方法 (Method for preparing heavy medium powder for high-performance coal dressing with different specifications in gradient mode by using refractory sulfuric acid cinder ) 是由 宛鹤 酒少武 屈娟萍 陈延信 卜显忠 杨玮 于 2021-02-07 设计创作，主要内容包括：一种难选硫酸烧渣梯级制备不同规格高性能选煤用重介质粉的方法,涉及固体废弃物的综合利用和环境保护领域,将难以用于钢铁冶炼的难选硫酸渣梯级制备成不同规格高性能选煤用重介质粉,实现了固体废弃物的综合利用,降低了固体废弃物对环境的影响,变废为宝,处理方法包括如下步骤：①难选硫酸烧渣制备焙烧原料；②悬浮态适时磁化焙烧；③焙烧矿梯级制备不同规格的选煤用重介质粉；④高性能选煤用重介质粉制备。本发明可获得5种不同品质高性能选煤用重介质粉,满足真密度大于4.5 g·cm～(-3)、磁性含量大于95%、-45μm组成含量大于80%,外在水分含量小于8%、硫分含量小于3%的选煤用重介质粉的要求。(A method for preparing heavy medium powder for high-performance coal separation with different specifications by refractory sulfuric acid cinder steps relates to the fields of comprehensive utilization of solid wastes and environmental protection, prepares refractory sulfuric acid cinder steps which are difficult to be used for steel smelting into heavy medium powder for high-performance coal separation with different specifications, realizes comprehensive utilization of the solid wastes, reduces the influence of the solid wastes on the environment, changes waste into valuable, and comprises the following steps: preparing roasting raw materials from refractory sulfuric acid cinder; secondly, magnetizing and roasting in a suspension state at proper time; thirdly, roasting the ore to prepare heavy medium powder for coal dressing with different specifications in a gradient manner; fourthly, preparing the dense medium powder for high-performance coal dressing. The invention can obtain 5 kinds of heavy medium powder with different qualities and high performance for coal dressing, and the true density is more than 4.5 g cm ‑3 More than 95% magnetic content and-45 μm magnetic contentThe content of the components is more than 80 percent, the external moisture content is less than 8 percent, and the sulfur content is less than 3 percent.)

1. The method for preparing the heavy medium powder for the high-performance coal dressing with different specifications in a gradient manner by using the refractory sulfuric acid cinder is characterized by comprising the following steps of:

(1) preparing a roasting raw material from refractory sulfuric acid cinder; (2) magnetizing and roasting in suspension state at proper time; (3) preparing heavy medium powder for coal dressing with different specifications by roasting ore in a gradient manner, and (4) preparing the heavy medium powder for high-performance coal dressing, wherein the refractory sulfuric acid roasted slag is waste slag generated in the process of preparing sulfuric acid by roasting pyrite.

2. The method for preparing roasting raw material from refractory sulfuric acid cinder preparation roasting raw material of claim 1, wherein the sulfuric acid cinder is ground to-100 mesh content of 100% by dry grinding.

3. The suspension timely magnetizing roasting of claim 1, characterized in that a suspension decomposing furnace with a preheating system and a multi-stage cyclone negative pressure cooling system is adopted for timely magnetizing roasting to reduce the weakly magnetic alpha, beta and sigma type ferric oxide in the roasted material into one or a mixture of ferroferric oxide or gamma type ferric oxide; wherein the timely magnetizing roasting temperature of the suspension state is 550-900 ℃, the roasting time is 1-60 seconds, the concentration of carbon monoxide in the reducing atmosphere is 1-15%, and the oxygen content is less than 5%.

4. The method for preparing the heavy medium powder for coal dressing in the gradient manner by roasting the ore as claimed in claim 1, is characterized in that the magnetic field intensity is controlled to be 300 Oe-1500 Oe, the magnetic field intensity of the ferromagnetic minerals in the roasted ore is recycled in the gradient manner from low to high, and the heavy medium powder for coal dressing in different specifications is prepared by partially recovering the gradient products according to a certain proportion.

5. The step recovery of magnetic field intensity from low to high of claim 4, characterized by that, (1) the first step is retrieved, adopt the magnetic field intensity of 300 Oe-500 Oe to carry on 1 rough 1 fine magnetic separation to the roasted ore, the magnetic separation concentrate is 1# heavy medium powder ore pulp for coal dressing, magnetic separation tailings and middlings are merged and regarded as the second step and utilized the raw materials; (2) performing second-step recovery, namely firstly performing ore grinding treatment on the second-step utilized raw materials, and then performing 1 coarse 1 fine magnetic separation treatment on the ground products by adopting a magnetic field intensity of 300 Oe-500 Oe, wherein the magnetic separation concentrate is heavy medium powder ore pulp for 2# coal separation, and magnetic separation tailings and middlings are combined to be used as third-step utilized raw materials, wherein the ore grinding fineness is controlled to be-400 meshes, and the content of the tailings accounts for 40% -90%; (3) performing third step recovery, namely performing 1 coarse 1 fine magnetic separation treatment on the third step utilization raw materials by adopting the magnetic field intensity of 500 Oe-800 Oe, wherein the magnetic separation concentrate is 3# heavy medium powder ore pulp for coal separation, and magnetic separation tailings and middlings are combined to serve as fourth step utilization raw materials; (3) and (3) recovering in a fourth step, wherein 1-time roughing treatment is carried out on the fourth step utilization raw materials by adopting the magnetic field intensity of 800 Oe-1500 Oe, 1-time fine selection treatment is carried out on coarse concentrate by adopting the magnetic field intensity of 600 Oe-1200 Oe, the magnetic concentrate is heavy medium powder ore pulp for 4# coal separation, and the magnetic tailings and the middlings are combined to be used as raw materials for cement or building materials.

6. The preparation method of the dense medium powder for high-performance coal separation as claimed in claim 1, characterized by separately controlling the mixture of the 1#, 2#, 3# and 4# dense medium powder pulp and one or more of starch, dextrin, sodium humate, tannin and other dispersing agents in claim 5 to act for 1-5 minutes in a stirring barrel, and obtaining the 1#, 2#, 3# and 4# dense medium powder for high-performance coal separation after concentration, filtration and suspension state drying, wherein other control variables in the stirring process are as follows: the temperature of the ore pulp is 20-50 ℃, the pH value of the ore pulp is 7-12, and the total dosage of the dispersing agent is 0.001-10 kg/ton of the heavy medium powder for coal dressing.

7. The number 1# -4 # in claim 6 is 4 heavy medium powders for high-performance coal separation with different qualities, and the heavy medium powders are characterized in that the 4 heavy medium powders for high-performance coal separation all meet the requirement that the true density is more than 4.5 g-cm^-3The magnetic content is more than 95 percent, the composition content of minus 45 mu m is more than 80 percent, the external moisture content is less than 8 percent, and the sulfur content is less than 3 percent; meanwhile, the true density of the material is from large to small: 2# 1 > 3# 4, the sulfur content is 2# 3# 1# 4# from large to small, the composition content of-45 μm is from large to small: 2# > 3# > 4# > 1 #.

Technical Field

A method for preparing heavy medium powder for high-performance coal separation with different specifications by refractory sulfuric acid cinder in a gradient manner relates to the field of comprehensive utilization of solid wastes and environmental protection, and prepares the refractory sulfuric acid cinder into the heavy medium powder for high-performance coal separation for coal separation in a gradient manner, thereby realizing comprehensive utilization of iron resources, reducing the influence of the solid wastes on the environment and changing the wastes into valuable.

Background

The sulfuric acid cinder is waste slag generated by roasting pyrite to prepare sulfuric acid, contains a large amount of ferric oxide resources, and the ferric oxide is converted from ferric sulfide through roasting, however, most of the ferric sulfide has the characteristics of fine granularity, serious coating and intergrowth with gangue, and the like, so the ferric oxide converted from the ferric sulfide also has the characteristics. Therefore, only a few magnetite powder with thick particle size and simple associated relationship can be produced by a simple magnetic separation process, and the like which meet the requirements of iron and steel smelting enterprises can be recovered by the acid manufacturing enterprises through the magnetizing roasting-magnetic separation process, and the rest is mostly used as cement and building material raw materials, so that the waste of iron resources is caused. Therefore, a low-cost and environment-friendly method is urgently needed to realize the comprehensive utilization of the refractory sulfuric acid cinder.

The heavy medium powder for coal dressing meets the requirement of the national standard that the true density is more than 4.5 g.cm^-3The magnetic content is more than 95 percent, the external moisture content is less than 8 percent, the sulfur content is less than 3 percent, and the magnetic powder is formed by certain granularity; the iron ore concentrate product produced by the refractory sulfuric acid cinder can not meet the national standard of iron ore concentrate of iron and steel smelting enterprises, but can meet the requirement of dense medium powder for coal dressing.

The phenomena of unstable medium density, aggravated weight consumption and the like in the coal dressing process are easily caused by the actions of magnetic agglomeration, nonselective adsorption and the like generated in the coal dressing process of the dense medium powder, so that the dense medium powder with high dispersion performance is obtained by modifying the conventional dense medium powder for coal dressing, the stability of the medium density in the coal dressing process is improved, and the consumption of the dense medium powder is reduced.

The existing technology of refractory sulfuric acid cinder is a refractory sulfuric acid cinder utilization method developed by aiming at obtaining iron ore concentrate for steel smelting with high grade and low impurity content, has the characteristics of high cost, complex technology and the like, and is not beneficial to comprehensive utilization of the refractory sulfuric acid cinder with low cost, low energy consumption, safety and environmental protection.

The invention discloses a method for preparing high-performance dense medium powder for coal separation with different specifications in a gradient manner by refractory sulfuric acid cinder, which aims to produce the high-performance dense medium powder for coal separation, develops gradient utilization of the refractory sulfuric acid cinder with low cost, low energy consumption, safety and environmental protection and a preparation method of the high-performance dense medium powder, realizes high-efficiency utilization of the refractory sulfuric acid cinder with low cost, low energy consumption, safety and environmental protection, and obtains the high-dispersion-performance dense medium powder for coal separation.

Disclosure of Invention

The method for utilizing the refractory sulfuric acid cinder and the iron ore concentrate produced by the refractory sulfuric acid cinder are difficult to meet the raw material requirements of iron and steel smelting enterprises, and the demand that the dense medium powder with high dispersion performance is urgently needed in the coal dressing process so as to improve the stability of the medium density in the coal dressing process and reduce the consumption of the dense medium powder is met. The invention aims to provide a method for preparing high-performance heavy medium powder for coal separation with different specifications in a gradient way by refractory sulfuric acid cinder, which aims to prepare modified heavy medium powder for coal separation with different specifications in a gradient way by refractory sulfuric acid cinder; various dense medium powders with high dispersion performance are also obtained, the stability of medium density in the coal dressing process is improved, and the consumption of the dense medium powders is reduced.

In order to achieve the above task, the present invention adopts the following technical solutions.

The invention relates to a method for preparing heavy medium powder for coal dressing with different specifications and high performance in a gradient manner by refractory sulfuric acid cinder, which comprises the following steps of (1) preparing a roasting raw material by refractory sulfuric acid cinder; (2) magnetizing and roasting in suspension state at proper time; (3) roasting ore to prepare heavy medium powder for coal dressing with different specifications in a gradient manner; (4) the preparation method comprises four steps of preparing the dense medium powder for high-performance coal dressing.

The roasting raw material prepared from the refractory sulfuric acid cinder in the step (1) is characterized in that the refractory sulfuric acid cinder is ground to-100 meshes by dry grinding until the content of the refractory sulfuric acid cinder accounts for 100%, wherein the refractory sulfuric acid cinder is waste residue generated in the process of roasting pyrite to prepare sulfuric acid.

Carrying out timely magnetizing roasting in the suspension state in the step (2), wherein a suspension state decomposing furnace with a preheating system and a multi-stage cyclone negative pressure cooling system is adopted for timely magnetizing roasting, and the weakly magnetic alpha, beta and sigma type ferric oxide in the roasting raw materials is reduced into one or a mixture of ferroferric oxide or gamma type ferric oxide; wherein the timely magnetizing roasting temperature of the suspension state is 550-900 ℃, the roasting time is 1-60 seconds, the concentration of carbon monoxide in the reducing atmosphere is 1-15%, and the oxygen content is less than 5%.

The step preparation of the dense medium powder for the alternative coal from the roasted ore in the step (3) is characterized in that the magnetic field intensity is controlled to be 300 Oe-1500 Oe, the magnetic field intensity of the ferromagnetic mineral in the roasted ore is subjected to step recovery from low to high, and the dense medium powder for the alternative coal is prepared from partial step recovery products according to a certain proportion. The method comprises the following steps:

firstly, first step recovery is carried out, 1 coarse 1 fine magnetic separation treatment is carried out on the ferromagnetic ore by adopting the magnetic field intensity of 300 Oe-500 Oe, the magnetic separation concentrate is 1# heavy medium powder ore pulp, and magnetic separation tailings and middlings are combined to be used as a second step utilization raw material;

secondly, carrying out second-step recovery, namely grinding the second-step utilized raw materials, carrying out 1 coarse 1 fine magnetic separation on the ground products by adopting a magnetic field intensity of 300 Oe-500 Oe, wherein the magnetic separation concentrate is 2# heavy medium powder ore pulp, magnetic separation tailings and middlings are combined to be used as third-step utilized raw materials, and the grinding fineness is controlled to be-400 meshes, and the content of the tailings accounts for 40% -90%;

thirdly, recycling in a third step, carrying out 1 coarse 1 fine magnetic separation treatment on the third step utilization raw materials by adopting the magnetic field intensity of 500 Oe-800 Oe, wherein the magnetic separation concentrate is 3# heavy medium powder ore pulp, and combining magnetic separation tailings and middlings to serve as a fourth step utilization raw material;

and fourthly, recovering in a fourth step, carrying out 1-time roughing treatment on the fourth step utilization raw materials by adopting the magnetic field intensity of 800 Oe-1500 Oe, carrying out 1-time fine selection treatment on coarse concentrate by adopting the magnetic field intensity of 600 Oe-1200 Oe, wherein the magnetic concentrate is No. 4 heavy medium powder ore pulp, and the magnetic tailings and the middlings are combined to be used as raw materials for cement or building materials.

The preparation method of the dense medium powder for high-performance coal separation is characterized in that the 1#, 2#, 3# and 4# dense medium powder ore pulp and one or more of starch, dextrin, sodium humate, tannin and other dispersing agents are respectively controlled to act for 1-5 minutes in a stirring barrel, and the 1#, 2#, 3# and 4# modified dense medium powder is obtained after concentration, filtration and suspension state drying, wherein other control variables in the stirring process are as follows: the temperature of the ore pulp is 20-50 ℃, the pH value of the ore pulp is 7-12, and the total dosage of the dispersing agent is 0.001-10 kg/ton of heavy medium powder. 4 kinds of modified dense medium powder with different qualities, which is characterized in that the 4 kinds of high-performance dense medium powder for coal dressing all meet the requirement that the true density is more than 4.5 g.cm^-3The magnetic content is more than 95 percent, the composition content of minus 45 mu m is more than 80 percent, the external moisture content is less than 8 percent, and the sulfur content is less than 3 percent; meanwhile, the true density of the material is from large to small: 2# 1 > 3# 4, the sulfur content is 2# 3# 1# 4# from large to small, the composition content of-45 μm is from large to small: 2# > 3# > 4# > 1 #.

Detailed Description

Gradient preparation of different specifications of heavy medium powder for high-performance coal separation from refractory sulfuric acid cinder example 1

Firstly, a certain refractory sulfuric acid cinder in Henan adopts a dry vertical mill to prepare a roasted ore raw material with 100 percent of-100 meshes and 60 percent of-200 meshes.

Tangentially feeding roasting raw materials into a suspension state decomposing furnace with a preheating system and a multi-stage cyclone negative pressure cooling system for timely magnetizing roasting, controlling the suspension state timely magnetizing roasting temperature to be 730-780 ℃, roasting time to be 5 seconds, reducing atmosphere carbon monoxide concentration to be 5-10%, oxygen content to be less than 1%, and cooling roasted ore to room temperature in a closed storage tank after multi-stage cyclone negative pressure cooling to be below 100 ℃.

Thirdly, first step recovery, the cooled roasted ore is prepared into ore pulp with the concentration of 30 percent, rough concentration is carried out under the magnetic field intensity of 400Oe, rough concentrate is finely selected under the magnetic field intensity of 350 Oe, the magnetic concentrate is 1# heavy medium powder ore pulp, and magnetic tailings and middlings are merged to be used as a second step utilization raw material.

And thirdly, second step recovery, namely, grinding the second step utilization raw materials, roughing under the magnetic field strength of 500Oe, selecting the rough concentrate under the magnetic field strength of 300 Oe, wherein the magnetic concentrate is 2# heavy medium powder ore pulp, combining the magnetic tailings and the middlings to serve as a third step utilization raw material, and controlling the grinding fineness to be-400 meshes and the content of the tailings to be 60%.

And fourthly, recovering in a third step, performing rough concentration on the raw materials in the second step under the magnetic field strength of 750Oe, performing fine concentration on rough concentrates under the magnetic field strength of 550 Oe, wherein the magnetic concentrate is 3# heavy medium powder ore pulp, and combining magnetic tailings and middlings to serve as a fourth step utilization raw material.

And fifthly, recovering in a fourth step, wherein the raw materials are roughly separated in the fourth step under the magnetic field intensity of 1500Oe, the rough concentrate is finely separated in the magnetic field intensity of 600 Oe, the magnetic concentrate is 4# heavy medium powder ore pulp, and the magnetic tailings and the medium ores are combined and can also be used as the raw materials for high-iron-content cement or building materials.

Sixthly, respectively controlling the 1#, 2#, 3# and 4# heavy medium powder pulp and starch to act in a stirring barrel for 2 minutes, and obtaining the 1#, 2#, 3# and 4# heavy medium powder for high-performance coal separation after concentration, filtration and suspension state drying, wherein other control variables are as follows in the stirring process: the temperature of the ore pulp is 25 ℃, the pH value of the ore pulp is 11, and the total using amount of starch is 0.5 kg/ton of heavy medium powder for coal dressing.

Seventhly, the true density of the 1# heavy medium powder for high-performance coal dressing is more than 4.5 g cm^-3The magnetic content is more than 99 percent, the composition content of minus 45 mu m is more than 80 percent, the external moisture content is less than 4 percent, and the sulfur content is less than 1.6 percent; the true density of the 2# high-performance dense medium powder for coal dressing is more than 4.8 g-cm^-3The magnetic content is more than 99 percent, the composition content of minus 45 mu m is more than 95 percent, the external moisture content is less than 6 percent, and the sulfur content is less than 0.6 percent; the true density of the 3# high-performance dense medium powder for coal dressing is more than 4.7 g cm^-3The magnetic content is more than 99 percent, the composition content of minus 45 mu m is more than 88 percent, the external moisture content is less than 5 percent, and the sulfur content is less than 0.8 percent; the true density of the heavy medium powder for 4# high-performance coal dressing is more than 4.65 g-cm^-3Magnetic content greater than 99%,The composition content of-45 mu m is more than 90 percent, the external moisture content is less than 5 percent, and the sulfur content is less than 1 percent.

Gradient preparation of heavy medium powder for high-performance coal separation with different specifications from refractory sulfuric acid cinder example 2

Firstly, roasted ore raw materials with 100 percent of-100 meshes and 55 percent of-200 meshes are prepared from certain refractory sulfuric acid cinder in Shaanxi by adopting a dry vertical mill.

Tangentially feeding roasting raw materials into a suspension state decomposing furnace with a preheating system and a multi-stage cyclone negative pressure cooling system for timely magnetizing roasting, controlling the suspension state timely magnetizing roasting temperature to be 800-850 ℃, the roasting time to be 10 seconds, the carbon monoxide concentration in a reducing atmosphere to be 8-13%, the oxygen content to be less than 0.5%, and cooling the roasted ore to room temperature in a sealed storage tank after the multi-stage cyclone negative pressure cooling to be below 100 ℃.

Thirdly, first step recovery, the cooled roasted ore is prepared into ore pulp with the concentration of 35 percent, rough concentration is carried out under the magnetic field strength of 500Oe, rough concentrate is finely selected under the magnetic field strength of 300 Oe, magnetic concentrate is 1# heavy medium powder ore pulp for coal separation, and magnetic tailings and middlings are combined to be used as a second step utilization raw material.

And thirdly, second step recovery, namely, grinding the second step utilization raw materials, roughing under the magnetic field intensity of 500Oe, finely selecting rough concentrate under the magnetic field intensity of 350 Oe, combining magnetic concentrate and middlings to serve as a third step utilization raw material, wherein the grinding fineness is controlled to be-400 meshes, and the content of the tailings accounts for 65%.

And fourthly, recovering in a third step, performing rough concentration on the raw materials in the second step under the magnetic field intensity of 800Oe, performing fine concentration on rough concentrates under the magnetic field intensity of 500Oe, wherein the magnetic concentrate is 3# heavy medium powder ore pulp for coal separation, and combining magnetic tailings and middlings to serve as a fourth step utilization raw material.

And fifthly, recovering in a fourth step, wherein the raw materials are roughly separated in the fourth step under the magnetic field intensity of 1400Oe, the rough concentrate is finely separated in the magnetic field intensity of 600 Oe, the magnetic concentrate is the heavy medium powder ore pulp for 4# coal separation, and the magnetic tailings and the medium ores can be combined to be used as the raw materials for high-iron-content cement or building materials.

Sixthly, respectively controlling the 1#, 2#, 3# and 4# heavy medium powder pulp for coal separation and sodium humate to act in a stirring barrel for 3 minutes, and obtaining 1#, 2#, 3# and 4# high-performance heavy medium powder for coal separation after concentration, filtration and suspension state drying, wherein other control variables in the stirring process are as follows: the temperature of the ore pulp is 30 ℃, the pH value of the ore pulp is 12, and the total consumption of the sodium humate is 1 kg/ton of the heavy medium powder for coal dressing.

Seventhly, the true density of the 1# heavy medium powder for high-performance coal dressing is more than 4.5 g cm^-3The magnetic content is more than 99 percent, the composition content of minus 45 mu m is more than 81 percent, the external moisture content is less than 3 percent, and the sulfur content is less than 1.5 percent; the true density of the 2# high-performance dense medium powder for coal dressing is more than 4.9 g cm^-3The magnetic content is more than 99 percent, the composition content of minus 45 mu m is more than 97 percent, the external moisture content is less than 6 percent, and the sulfur content is less than 0.5 percent; the true density of the 3# high-performance dense medium powder for coal dressing is more than 4.7 g cm^-3The magnetic content is more than 99 percent, the composition content of minus 45 mu m is more than 92 percent, the external moisture content is less than 5 percent, and the sulfur content is less than 1 percent; the true density of the heavy medium powder for 4# high-performance coal dressing is more than 4.65 g-cm^-3The magnetic content is more than 99 percent, the composition content of minus 45 mu m is more than 82 percent, the external moisture content is less than 5 percent, and the sulfur content is less than 1 percent.