阅读说明：本技术 一种赤泥与硫化矿物协同处置及资源化利用方法 (Red mud and sulfide mineral co-processing and resource utilization method ) 是由 胡学伟 李柳青 田森林 黄建洪 李英杰 宁平 于 2019-11-21 设计创作，主要内容包括：本发明公开了一种赤泥与硫化矿物协同处置及资源化利用方法,所述方法包括：(1)赤泥经洗液淋洗及固液分离,得到碱性淋洗液；(2)含硫化矿物的物料经氧化浸出及固液分离,得到酸性浸出液；(3)将碱性淋洗液与酸性浸出液混合,进行酸碱中和及固液分离,得到金属氢氧化物沉淀；(4)中和反应出水部分回流用于赤泥的持续淋洗脱碱,部分回流用于金属硫化矿的持续氧化产酸,直至赤泥脱碱及硫化矿浸出完成；(5)金属氢氧化物沉淀经脱水可资源化回收。本发明通过金属硫化矿的氧化制硫酸与赤泥的淋洗产碱,经酸碱中和及氢氧化物沉淀,不仅实现赤泥生化脱碱,同时还可实现赤泥与低品位硫化矿中有价金属的资源化回收,设备要求简单、反应条件温和、运行成本低。(The invention discloses a cooperative treatment and resource utilization method of red mud and sulfide minerals, which comprises the following steps: (1) leaching the red mud with a washing solution and performing solid-liquid separation to obtain an alkaline leaching solution; (2) carrying out oxidation leaching and solid-liquid separation on the material containing the sulfide minerals to obtain an acidic leaching solution; (3) mixing the alkaline leacheate with the acidic leaching solution, and performing acid-base neutralization and solid-liquid separation to obtain metal hydroxide precipitate; (4) part of the effluent of the neutralization reaction is refluxed for continuous leaching dealkalization of the red mud, and part of the effluent is refluxed for continuous oxidation acidogenesis of the metal sulfide ore until the dealkalization of the red mud and leaching of the sulfide ore are finished; (5) the metal hydroxide precipitate can be recycled after dehydration. The invention produces alkali by leaching sulfuric acid and red mud through the oxidation of metal sulfide ore, realizes the biochemical dealkalization of the red mud and the resource recovery of valuable metals in the red mud and low-grade sulfide ore through acid-base neutralization and hydroxide precipitation, and has simple equipment requirement, mild reaction condition and low operation cost.)

1. A cooperative treatment and resource utilization method of red mud and sulfide minerals is characterized by comprising the following steps:

(1) leaching the red mud with a washing solution and performing solid-liquid separation to obtain an alkaline leaching solution;

(2) carrying out oxidation leaching and solid-liquid separation on the material containing the sulfide minerals to obtain an acidic leaching solution;

(3) mixing the red mud alkaline leacheate with the sulfide ore acidic leaching solution, and performing acid-base neutralization and solid-liquid separation to obtain metal hydroxide precipitate;

(4) part of the effluent of the neutralization reaction is refluxed for continuous leaching dealkalization of the red mud, and part of the effluent is refluxed for continuous oxidation acidogenesis of the metal sulfide ore until the dealkalization of the red mud and leaching of the sulfide ore are finished;

(5) the metal hydroxide precipitate can be recycled after dehydration.

2. The cooperative treatment and resource utilization method for the red mud and the sulfide minerals according to claim 1, wherein the red mud in the step (1) comprises any one or more of bayer process red mud, sintering process red mud and combination process red mud.

3. The cooperative treatment and resource utilization method for the red mud and the sulfide minerals according to claim 1, wherein the pH of the alkaline leacheate obtained in the step (1) is more than 7.0, and the pH of the acidic leachate obtained in the step (2) is 1.0-5.0.

4. The cooperative treatment and resource utilization method for the red mud and the sulfide minerals according to claim 1, wherein the washing solution in the step (1) can be clear water, industrial wastewater and effluent of neutralization reaction.

5. The red mud and sulfide mineral co-processing and resource utilization method according to claim 1, wherein the sulfide mineral-containing material in step (2) comprises sulfide minerals containing iron, manganese, copper, zinc, lead or nickel.

6. The cooperative treatment and resource utilization method for the red mud and the sulfide minerals according to claim 1, wherein the sulfide minerals in the sulfide mineral-containing material in the step (2) have a grade of 0.1-50% and a particle size of 0.05-2 mm.

7. The cooperative treatment and resource utilization method of red mud and sulfide minerals according to claim 1, wherein the leaching manner of the oxidation leaching in the step (2) comprises natural oxidation leaching and/or biological oxidation leaching, and the biological oxidation microorganism comprises sulfur oxidizing bacteria, iron oxidizing bacteria or a mixed strain of the sulfur oxidizing bacteria and the iron oxidizing bacteria.

8. The cooperative treatment and resource utilization method for the red mud and the sulfide minerals according to claim 7, characterized in that the initial pH of the biological oxidation leaching in the step (2) is 1.5-6.0, the temperature of the leaching environment is 15-45 ℃, the humidity of the leaching environment is 40% -90%, the volume ratio of the biological inoculation amount to the water amount required by leaching is (0.1-2): 5, and the concentration of the bacteria liquid is 10⁶~10⁹cfu/mL。

9. The cooperative treatment and resource utilization method for the red mud and the sulfide minerals according to claim 1, wherein the pH value of the neutralization precipitation reaction in the step (4) is 3.5-10.

10. The cooperative treatment and resource utilization method for the red mud and the sulfide minerals according to claim 1, wherein the red mud leaching and the sulfide ore bioleaching in the step (4) are performed, and the reaction is completed when the red mud and the sulfide ore meet the index requirement.

Technical Field

The invention belongs to the technical field of solid waste treatment, and particularly relates to a method for cooperative treatment and resource utilization of red mud and sulfide minerals.

Background

The red mud is industrial solid waste produced in the process of producing alumina by bauxite alkali leaching, has the characteristics of strong alkalinity, fine granularity and the like, has the characteristics of dangerous solid waste, and easily causes environmental problems of land alkalization, underground water pollution, alkaline dust emission and the like in the conventional red mud yard stacking mode.

The existing red mud dealkalization technologies comprise a lime dealkalization method, a membrane dealkalization method, a lime hydrothermal method and the like. The lime dealkalization method utilizes Ca in lime²⁺With OH in red mud^-、CO₃ ^2-Forming a precipitate to remove the alkalinity of the red mud; the method has low removal efficiency, and the precipitate is wrapped on the outer layer of the red mud, so that when the environmental condition is changed, the precipitate can be dissolved out again to release alkalinity. The membrane dealkalization method separates red mud slurry and pure separating agent by means of semipermeable membrane to make Na in red mud⁺、K⁺And alkaline earth metal ions permeate the semipermeable membrane and enter the dispersing agent to be removed; the method has the problems that membrane holes are easy to pollute and block, the membrane replacement cost is high and the like. The lime hydrothermal method is to make lime or CaO-containing mineral directly act with red mud to cause lattice substitution reaction, Na⁺Quilt Ca²⁺The substitution forms a new compound, thereby making a part of Na⁺Transferring the red mud into an aqueous solution to reduce the alkalinity of the red mud; the method needs high temperature (about 270 ℃) and long reaction time, thereby increasing the operation cost and being not suitable for large-scale treatment of the red mud.

A large amount of tailings generated in the mining process of a mine and coal gangue discharged in the coal mining process are widely stockpiled or discarded in the forms of pyrite, low-grade sulphide ore and the like, and are oxidized to generate sulfuric acid and a metal sulfate solution after being in contact reaction with air, sulfur oxidizing bacteria, iron oxidizing bacteria and the like, so that not only is underground water and soil polluted, but also waste of acid and metal resources is caused if the treatment is improper.

The invention patent with application publication number CN103031443A discloses a method for dealkalizing red mud and recovering aluminum and iron. The invention uses red mud and sulfuric acid to mix and precipitate, filters the precipitation liquid, and then uses resin to absorb and filter iron and aluminum in the supernatant. Sulfuric acid is required to be added to react with the red mud in the process, the cost of the sulfuric acid and resin is high, and the problems of resin pollution and desorption are required to be solved.

The invention patent with application publication number CN109433213A discloses a method for selectively dealkalizing red mud and enriching iron. The invention directly adds acid to mix with red mud, filters the mixed liquid, washes to neutrality, and dries to obtain red mud filter cake. The method also needs to add a large amount of sulfuric acid, iron is enriched in the red mud without realizing the recovery of iron resources, the cost of the operation place is high, and metal resources are wasted.

The invention patent with the publication number of CN102671906B discloses a method for treating coal gangue and red mud. The invention alternately stacks the coal gangue and the red mud layer by layer, so that the coal gangue and the red mud are neutralized with each other. According to the method, only the red mud and the coal gangue are alternately stacked, the reaction time is long, the reaction is incomplete, the harmful components in the coal gangue and the red mud are released again, secondary pollution is caused to the environment, and the stacking mode enables the reaction heat of the coal gangue not to be dissipated, so that the spontaneous combustion risk is caused; the metal elements in the coal gangue and the red mud can not be recovered, thereby causing resource waste.

The invention patent with application publication number CN103073066A discloses a method for harmless treatment and resource utilization of red mud. The invention carries out high-temperature roasting and acid leaching treatment on the red mud, and then separates valuable metals in the red mud; and adding coal gangue into the remaining red mud residue, and sintering at a high temperature to prepare the baked brick. The method carries out high-temperature roasting on the red mud, and has large energy consumption; because acid is directly added for acid leaching treatment, the red mud treatment operation cost is high; the coal gangue is added into the red mud residue to prepare the baked brick, the utilization rate of the coal gangue is low, and the problem of environmental pollution generated in the solid waste disposal process cannot be thoroughly and timely solved.

Therefore, a method for the cooperative disposal and resource utilization of red mud and sulfide minerals is urgently needed to be provided.

Disclosure of Invention

The invention aims to provide a method for cooperative treatment and resource utilization of red mud and sulfide minerals. The principle of the invention is as follows: the red mud is leached and oxidized to generate metal-containing alkali liquor; leaching the material containing metal sulfide ore by using microorganism or natural oxidation, wherein the reaction product is H₂SO₄And metal ions, neutralizing and precipitating the metal ions and red mud leaching alkali liquor to obtain a precipitate of metal hydroxide; part of the water discharged from the neutralization reaction flows back, and the red mud is continuously and circularly leached to be dealkalized and harmless; the reflux of the neutralized effluent can maintain the optimal pH value range of the bioleaching; the metal hydroxide can be obtained after dehydrationAnd (5) recycling.

The invention is realized by the following technical scheme:

(1) leaching the red mud with a washing solution and performing solid-liquid separation to obtain an alkaline leaching solution;

(2) carrying out oxidation leaching and solid-liquid separation on the material containing the sulfide minerals to obtain an acidic leaching solution;

(3) mixing the red mud alkaline leacheate with the sulfide ore acidic leaching solution, and performing acid-base neutralization and solid-liquid separation to obtain metal hydroxide precipitate;

(4) part of the effluent of the neutralization reaction is refluxed for continuous leaching dealkalization of the red mud, and part of the effluent is refluxed for continuous oxidation acidogenesis of the metal sulfide ore until the dealkalization of the red mud and leaching of the sulfide ore are finished;

(5) the metal hydroxide precipitate can be recycled after dehydration.

The red mud in the step (1) comprises Bayer process red mud, sintering process red mud and combination process red mud, and preferably Bayer process red mud.

Leaching the red mud obtained in the step (1) with a leaching solution, and performing solid-liquid separation to obtain the leaching solution, wherein the pH value of the leaching solution is greater than 7.0, and preferably 8.5-11.

And (2) leaching the washing solution in the step (1), wherein the washing solution can be clear water, weak alkaline water, industrial wastewater, neutralization reaction effluent and the like, and is preferably clear water.

The material containing sulphide minerals in the step (2) comprises materials containing sulphide minerals such as iron, manganese, copper, zinc, lead, nickel and the like, and is preferably iron sulphide minerals.

Biologically oxidizing and leaching the sulfide mineral-containing material in the step (2), wherein the sulfide ore grade is 0.1-50%, and preferably 10-30%; the particle size is 0.05 to 2mm, preferably 0.15 to 1 mm.

And (3) biologically oxidizing and leaching the material containing the sulfide minerals in the step (2), wherein microorganisms comprise sulfur oxidizing bacteria, iron oxidizing bacteria and mixed strains of the sulfur oxidizing bacteria and the iron oxidizing bacteria, and preferably sulfur oxidizing bacteria, sulfur ferrous oxide bacteria and mixed strains of the sulfur oxidizing bacteria and the iron oxidizing bacteria.

Performing biological oxidation leaching in the step (2), wherein the initial pH is 1.5-6.0, and preferably 2.0-3.0; the leaching environment temperature is 15-45 ℃, preferably 25-30 DEG C(ii) a The humidity of the leaching environment is 40% -90%, and preferably 60% -70%; the volume ratio of the biological inoculation amount to the water amount required by leaching is (0.1-2) to 5, preferably (0.05-0.1): 1; bacterial liquid concentration of 10⁶~10⁹cfu/mL, preferably 10⁷~10⁸cfu/mL。

And (3) biologically oxidizing and leaching the sulfide mineral-containing material in the step (2), wherein the pH of a biological leaching solution is 1.0-5.0, and preferably 2.0-3.0.

And (4) the pH value of the neutralization precipitation reaction is 3.5-10, and preferably 3.7-5.5.

The invention has the beneficial effects that:

(1) the material containing metal sulfide ore is biologically oxidized or naturally oxidized by using microorganisms, so that the acid is generated at low cost.

(2) The red mud is continuously leached through partial reflux of acid-base neutralization effluent, and the red mud is dealkalized with high efficiency.

(3) Leaching the red mud and leaching out low-grade sulfide minerals, thereby realizing resource recovery of valuable metal elements.

(4) The acid production, dealkalization and valuable metal recovery are continuously and circularly carried out, the process is simple, and the operation cost is low.

(5) The red mud and the waste sulfide minerals are cooperatively treated, so that the waste treatment by waste is realized.

(6) No harmful substance is discharged in the reaction, and no secondary pollution is caused.

(7) The comparison between the treatment method of the invention and natural stockpiling, chemical oxidation and the existing comprehensive utilization means is shown in the following table:

natural piling up	Chemical oxidation	Comprehensive utilization of	The treatment method of the invention
				The sulfide minerals are mixed with the red mud under natural conditions Stacking layer by layer to generate neutralization reaction Should be used.	E.g. acid leaching, directly Adding acid to generate with red mud And (4) neutralizing.	Jointly utilizing red mud and coal gangue Preparing sintered bricks, cement and the like.	Oxidizing and leaching the material containing the metal sulfide ore, neutralizing and precipitating the reaction product with red mud leaching alkali liquor to obtain gold Precipitation of metal hydroxides; the metal hydroxide can be recycled after dehydration.
The heat produced by oxidation of sulfide cannot be discharged in time and is easy to be discharged Causing spontaneous combustion and releasing a large amount of CO, H2S, SO2, NOx and other toxic and harmful gases.	Directly adding acid to perform reaction It should be costly to operate.	Low utilization rate, and can not thoroughly and timely Solving the problem of solid waste generated in the disposal process And (5) the environmental pollution problem.	Oxidizing and leaching sulfide minerals by using microorganisms, wherein the reaction speed is 10 oxidized under natural conditions6 The reaction is mild, no harmful substance is released, and the operation cost is low; the reaction can be carried out circularly, and the red mud is dealkalized Thoroughly and simultaneously realizes deacidification and weight removal of the sulfurized minerals.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

The invention is pre-tested, and the test is as follows:

(1) preparing a culture medium: the culture medium is 9K culture medium with composition of 3.0g (NH)₄)₂SO₄, 0.1g KCl, 5gK₂HPO₄, 0.5g MgSO₄·7H₂O， 0.01g Ca(NO₃)₂No ferrous sulfate is added.

(2) Test samples: naturally air-dried pyrite and red mud are selected, ground and sieved by a 100-mesh sieve, and the particle size is 0.15 mm.

(3) And (3) test operation: placing 5g of red mud and 5g of pyrite in 250mL conical flasks respectively; adding 100mL of deionized water into the red mud, and measuring the pH value to be 7.0; adding the prepared culture medium 10 into pyrite0mL with 1:1H₂SO₄Adjusting the pH to 2.5; placing the red mud and pyrite reactor on a shaking bed to shake at a rotating speed of 120r/min, and monitoring the pH change of the reactor. The pH of the supernatant of the red mud reaches 10.5, when the pH of the bioleaching solution reaches 1.5, the bioleaching solution is respectively subjected to solid-liquid separation, the acidic leaching solution and the alkaline leacheate are mixed in a 250mL conical flask, and 1:1H is added₂SO₄By adjusting the pH to 3.5, iron hydroxide precipitation in the flask was observed.

The above tests show that the microorganisms can leach heavy metals and acidic components in the pyrite to produce an acidic leachate; the red mud can be washed by water to remove the alkalinity thereof to generate alkaline leacheate; the acidic leachate and the alkaline leacheate generate ferric hydroxide precipitate at the pH value of 3.5 after being mixed, and the metal elements in the pyrite can be recovered through neutralization reaction. This test demonstrates the feasibility of the invention.

The invention is further illustrated by the following examples, which are not intended to be limiting in any way, and any alterations and modifications based on the teachings of the invention are intended to be covered by the invention.