阅读说明：本技术 一种利用硫铁矿焙烧处理含氰废渣回收铁精矿的方法 (Method for recovering iron ore concentrate by roasting cyanogen-containing waste residues with pyrite ) 是由 孙浩飞 刘占林 王建政 朱德兵 孙学平 温希松 焦磊 王敏杰 郭建东 于 2021-07-12 设计创作，主要内容包括：本发明公开了一种利用硫铁矿焙烧处理含氰废渣回收铁精矿的方法,根据含氰废渣中含有氰化物、砷及重金属等多种污染物的特征,首先选用调浆工艺,按照一定的硫铁矿与含氰废渣混合加调浆液调成泥浆；然后将矿浆输送至焙烧炉,进行还原焙烧预处理流程,焙烧脱除氰化物、砷及重金属等污染物；二氧化硫烟气采用传统硫酸生产技术生产工业硫酸；焙烧尾矿经过磁选工艺回收铁精矿,铁回收率达80％以上。磁选后尾渣为一般固体废弃物,堆至尾矿库存储,废水进入调浆池闭路循环调浆,制酸废气达标排放。(The invention discloses a method for recovering iron ore concentrate by roasting cyanide-containing waste residues by utilizing pyrite, which comprises the steps of firstly selecting a size mixing process according to the characteristics of various pollutants such as cyanide, arsenic, heavy metal and the like in the cyanide-containing waste residues, mixing the pyrite and the cyanide-containing waste residues according to a certain amount, adding size mixing liquid, and mixing into slurry; then conveying the ore pulp to a roasting furnace, carrying out reduction roasting pretreatment flow, and roasting to remove pollutants such as cyanide, arsenic and heavy metal; the sulfur dioxide flue gas adopts the traditional sulfuric acid production technology to produce industrial sulfuric acid; the roasted tailings are subjected to a magnetic separation process to recover iron concentrate, and the iron recovery rate is over 80 percent. After magnetic separation, tailings are common solid wastes, the tailings are piled to a tailing pond for storage, wastewater enters a size mixing pond for closed cycle size mixing, and acid-making waste gas reaches the standard and is discharged.)

1. A method for recovering iron ore concentrate by roasting and treating cyanide-containing waste residues with pyrite is characterized by comprising the following steps:

1) mixing pyrite and cyanide-containing waste residues in a stirring tank to prepare a mixed solid material under a stirring state, adding a blending slurry into the stirring tank to prepare ore slurry with the mass percent of 65-75%, and ensuring that the stirring time is 4-6 hours;

2) discharging the ore pulp mixed in the step 1) from the stirring tank in a stirring state, screening out large-particle minerals by using a vibrating screen with the diameter of 0.8-1.0mm, and conveying the ore pulp under the screen to a fluidized bed roaster for roasting by using a pump;

3) purifying, converting, absorbing and other procedures of the flue gas containing sulfur dioxide, sulfur trioxide, fine-grained mine dust and the like, which is produced by roasting in the step 2), through a traditional acid making process to produce an industrial sulfuric acid product;

4) directly feeding the iron-containing calcine obtained by roasting in the step 2) into a cooling process, adjusting the mass percentage to be 20-40% of ore concentration, adding lime to adjust the pH value, conveying the mixture to a magnetic separator, and carrying out magnetic separation to obtain iron ore concentrate containing 55-65% of iron.

2. The method for recovering the iron ore concentrate by using the pyrite roasting treatment cyanide-containing waste residue according to claim 1, wherein the ratio of the pyrite to the cyanide-containing waste residue in the step 1) is 1: 0.8-1: 1, and the prepared mixed solid material contains 27-30% of sulfur.

3. The method for recovering the iron ore concentrate by using the pyrite roasting treatment cyanide-containing waste residue according to claim 1, wherein the roasting temperature in the step 2) is 700-800 ℃.

4. The method for recovering the iron ore concentrate by using the pyrite roasting to treat the cyanide-containing waste residues according to claim 1, wherein the oxygen supply amount in the roasting furnace in the step 2) is 80-90% of the total oxygen amount required by the complete combustion of the materials.

5. The method for recovering the iron ore concentrate by using the pyrite roasting treatment cyanide-containing waste residue according to claim 1, wherein the roasting reaction time in the step 2) is 15-30 min.

6. The method for recovering the iron ore concentrate by using the pyrite roasting treatment cyanide-containing waste residue according to claim 1, wherein lime is added in the step 4) to adjust the pH value to 5-7.

7. The method for recovering the iron ore concentrate by using the pyrite roasting treatment cyanide-containing waste residue according to claim 1, wherein the flow rate of the ore pulp during the magnetic separation in the step 4) is 5-10 t/h, and the magnetic field intensity is 180-250 mT.

8. The method for recovering the iron ore concentrate by using the pyrite roasting treatment cyanide-containing waste residue according to claim 1, wherein the size mixing liquid in the step 1) is the tail liquid after the magnetic separation of iron in the step 4), and the tail liquid enters a size mixing tank for closed-loop circulation size mixing.

Technical Field

The invention belongs to the technical field of environment-friendly recovery of tailings, and particularly relates to a method for recovering iron ore concentrate by roasting cyanogen-containing waste residues with pyrite.

Background

The cyanogen-containing waste residues mainly come from industries such as gold, electroplating and the like, for example: the cyaniding leaching process in the gold industry can generate a large amount of cyanide-containing tailings, and the cyanide-containing tailings contain high-concentration cyanide, heavy metal and other pollutants, and more than 95 percent of the cyanide-containing tailings are dangerous wastes after toxicity leaching identification.

At present, the comprehensive treatment technology of cyanide-containing waste residues is not many, the pulp conditioning treatment is mainly used, and the methods for carrying out the comprehensive treatment after the pulp conditioning mainly comprise a hydrogen peroxide method, a sodium hypochlorite method, a sodium pyrosulfite method and the like. The sulfur dioxide in the tail gas is mainly absorbed by alkali liquor, but the treatment cost is relatively high, and each treatment method has limitations.

Disclosure of Invention

According to the defects of the prior art, the invention aims to provide the method for recovering the iron ore concentrate by roasting the cyanide-containing waste residues with the pyrite, which has simple process flow and high treatment efficiency, so as to realize the comprehensive recovery of the iron in the pyrite and the cyanide waste residues.

In order to achieve the purpose, according to the characteristics of various pollutants such as cyanide, arsenic, heavy metal and the like in the cyanide-containing waste residue, firstly, a size mixing process is selected, and the size mixing liquid is added to mix the pyrite and the cyanide-containing waste residue according to a certain proportion to prepare slurry; then conveying the ore pulp to a roasting furnace, carrying out reduction roasting pretreatment flow, and roasting to remove pollutants such as cyanide, arsenic and heavy metal; the sulfur dioxide flue gas adopts the traditional sulfuric acid production technology to produce industrial sulfuric acid; and recovering iron ore concentrate from the roasted tailings by a magnetic separation process. And the identification result is that the tailings slag of which the magnetic separation tailings are common solid wastes is piled up to a tailing pond, and clear liquid is discharged after reaching the standard or enters a size mixing process for circular size mixing.

The adopted specific technical scheme is as follows:

a method for recovering iron ore concentrate by roasting and treating cyanide-containing waste residues with pyrite comprises the following steps:

1) mixing pyrite and cyanide-containing waste residues in a stirring tank to prepare a mixed solid material under a stirring state, adding a blending slurry into the stirring tank to prepare ore slurry with the mass percent of 65-75%, and ensuring that the stirring time is 4-6 hours;

2) discharging the ore pulp mixed in the step 1) from the stirring tank in a stirring state, screening out large-particle minerals by using a vibrating screen with the diameter of 0.8-1.0mm, and conveying the ore pulp under the screen to a fluidized bed roaster for roasting by using a pump;

3) purifying, converting, absorbing and other procedures of the flue gas containing sulfur dioxide, sulfur trioxide, fine-grained mine dust and the like, which is produced by roasting in the step 2), through a traditional acid making process to produce an industrial sulfuric acid product;

4) directly feeding the iron-containing calcine obtained by roasting in the step 2) into a cooling process, adjusting the mass percentage to be 20-40% of ore concentration, adding lime to adjust the pH value, conveying the mixture to a magnetic separator, and carrying out magnetic separation to obtain iron ore concentrate containing 55-65% of iron.

Preferably, the ratio of the pyrite to the cyanide-containing waste residue in the step 1) is 1: 0.8-1: 1, and the prepared mixed solid material contains 27-30% of sulfur.

Preferably, the slurry mixing in the step 1) is tail liquid obtained after magnetic separation in the step 4), and the tail liquid enters a slurry mixing tank for closed-loop circulating slurry mixing.

Preferably, in the step 2), the roasting temperature is 700-800 ℃, the oxygen supply amount in the roasting furnace is 80-90% of the total oxygen amount required by the complete combustion of the material, and the roasting reaction time is 15-30 min.

Preferably, lime is added in the step 4) to adjust the pH value to be 5-7, the flow rate of ore pulp during magnetic separation is 5-10 t/h, and the magnetic field intensity is 180-250 mT.

The invention has the beneficial effects that:

(1) according to the roasting process of the pyrite and the characteristics of the cyanide-containing waste residues, the thinking of roasting treatment and comprehensive recovery of iron is adopted, the roasting of the pyrite and the purification treatment of the cyanide-containing waste residues of enterprises are combined, and the comprehensive recovery of iron in the pyrite and the cyanide-containing waste residues is realized.

(2) The method mainly adopts a tail liquid size mixing technology, a reduction roasting treatment technology and a comprehensive recovery technology of valuable element iron to perform advanced treatment on the cyanide-containing waste residues of the gold mine in cooperation, has the advantages of good treatment effect, high treatment efficiency, stable system operation and simple process flow, is convenient for realizing industrial application, produces iron ore concentrate after treatment, piles the tail residues after magnetic separation into a tailing pond for storage, feeds the waste water into a size mixing pond for closed cycle size mixing, and discharges the acid-making waste gas up to the standard.

Detailed Description

The present invention is described below with reference to examples, which are provided for illustration only and are not intended to limit the scope of the present invention.

Example 1

The water content of the cyanide-containing tailings of an enterprise is 35%, the iron content is 32%, the sulfur content is 2.5%, the tailings are subjected to toxicity leaching, the pH of the overproof components of the leachate is 10.69, the CNT is 158.8mg/L, and the toxic leaching result is dangerous waste. The pyrite mainly contains 43% of sulfur and 39.6% of iron. Under the stirring state, mixing pyrite and cyanogen-containing waste residues according to the ratio of 1:0.8 of the pyrite to the cyanogen-containing waste residues to prepare a mixed solid material containing 25.2% of sulfur, adding the size mixing liquid into a stirring tank to prepare ore pulp with the mass percentage of 65%, and ensuring that the stirring time is 4 hours; discharging the pulp after size mixing from a stirring tank under the stirring state, screening large-particle minerals by a vibrating screen with the diameter of 0.8mm, conveying the pulp under the screen to a fluidized bed roaster by a pump, controlling the roasting temperature at 700 ℃, supplying oxygen to 80% of the total oxygen required by the complete combustion of the materials, fully ensuring the reduction roasting atmosphere, and reacting for 15 min; flue gas containing sulfur dioxide, sulfur trioxide, fine-grained mine dust and the like, which is produced by roasting, is subjected to the working procedures of purification, conversion, absorption and the like of the traditional acid making process to produce an industrial sulfuric acid product; directly feeding the iron-containing calcine produced by roasting into a cooling process, adjusting the concentration of the iron-containing calcine to be 20% in percentage mass ratio, adding lime to adjust the pH value to be 5, conveying the iron-containing calcine to a magnetic separator, controlling the flow rate of ore pulp to be 5t/h and the magnetic field intensity to be 180mT, producing iron ore concentrate containing 55% of iron and 0.3% of sulfur through magnetic separation, wherein the iron recovery rate is 85.5%, tailings after the magnetic separation are common solid waste, piling the solid waste into a tailing pond for storage, and feeding wastewater into a pulp mixing pond for closed-loop circulation pulp mixing.

Example 2

The water content of the cyanide-containing tailings of an enterprise is 30%, the iron content is 35%, the sulfur content is 1.0%, the tailings are subjected to toxic leaching, the pH of the overproof components of the leachate is 11.65, the CNT is 189.6mg/L, and the toxic leaching result is dangerous waste. The pyrite mainly contains 49% of sulfur and 41.2% of iron. Under the stirring state, mixing pyrite and cyanogen-containing waste residues according to the ratio of 1:0.85, preparing a mixed solid material containing 27% of sulfur, adding the blending slurry into a stirring tank to prepare an ore slurry with the mass percentage of 70%, and ensuring that the stirring time is 5 hours; discharging the pulp after size mixing from a stirring tank under the stirring state, screening large-particle minerals by a vibrating screen with the diameter of 0.8mm, conveying the pulp under the screen to a fluidized bed roaster by a pump, controlling the roasting temperature at 750 ℃, supplying oxygen to 85% of the total oxygen required by the complete combustion of the materials, fully ensuring the reduction roasting atmosphere, and ensuring the reaction time to be 25 min; flue gas containing sulfur dioxide, sulfur trioxide, fine-grained mine dust and the like, which is produced by roasting, is subjected to the working procedures of purification, conversion, absorption and the like of the traditional acid making process to produce an industrial sulfuric acid product; directly feeding the iron-containing calcine produced by roasting into a cooling process, adjusting the concentration of the iron-containing calcine to be 30% in percentage mass ratio, adding lime to adjust the PH to be 6, conveying the iron-containing calcine to a magnetic separator, controlling the flow rate of ore pulp to be 8t/h and the magnetic field intensity to be 220mT, producing iron ore concentrate containing 60% of iron and 0.29% of sulfur through magnetic separation, wherein the iron recovery rate is 82.30%, tailings after the magnetic separation are common solid waste, piling the solid waste into a tailing pond for storage, and feeding wastewater into a pulp mixing pond for closed-loop circulation pulp mixing.

Example 3

The water content of the cyanide-containing tailings of an enterprise is 28%, the iron content is 40%, the sulfur content is 6.2%, the tailings are subjected to toxicity leaching, the pH of the overproof pollutant component of the leachate is 12.65, the CNT is 239.6mg/L, and the toxicity leaching result is dangerous waste. The pyrite mainly contains 51% of sulfur and 43.2% of iron. Under the stirring state, mixing pyrite and cyanogen-containing waste residues according to the ratio of 1:1 of pyrite to cyanogen-containing waste residues to prepare a mixed solid material containing 28.6% of sulfur, adding the blending slurry into a stirring tank to prepare an ore slurry with the mass percentage of 75%, and ensuring that the stirring time is 6 hours; discharging the pulp after size mixing from a stirring tank under the stirring state, screening large-particle minerals by a vibrating screen with the diameter of 1.0mm, conveying the pulp under the screen to a fluidized bed roaster by a pump, controlling the roasting temperature at 800 ℃, supplying oxygen to 90% of the total oxygen required by the complete combustion of the materials, fully ensuring the reduction roasting atmosphere, and reacting for 30 min; flue gas containing sulfur dioxide, sulfur trioxide, fine-grained mine dust and the like, which is produced by roasting, is subjected to the working procedures of purification, conversion, absorption and the like of the traditional acid making process to produce an industrial sulfuric acid product; directly feeding the iron-containing calcine produced by roasting into a cooling process, adjusting the concentration of the iron-containing calcine to 40% in percentage mass ratio, adding lime to adjust the pH value to 7, conveying the iron-containing calcine to a magnetic separator, controlling the flow rate of ore pulp to be 10t/h and the magnetic field intensity to be 250mT, producing iron ore concentrate containing 65% of iron and 0.28% of sulfur through magnetic separation, wherein the iron recovery rate is 82.6%, tailings after the magnetic separation are common solid wastes, piling the solid wastes into a tailing pond for storage, and feeding wastewater into a pulp mixing pond for closed-loop circulation pulp mixing.

Comparative example 1

The water content of the cyanide-containing tailings of an enterprise is 35%, the iron content is 32%, the sulfur content is 2.5%, the tailings are subjected to toxicity leaching, the pH of the overproof components of the leachate is 10.69, the CNT is 158.8mg/L, and the toxic leaching result is dangerous waste. The pyrite mainly contains 43% of sulfur and 39.6% of iron. Under the stirring state, mixing pyrite with cyanogen-containing waste residues according to the proportion of 1:0.5, preparing a mixed solid material containing 16% of sulfur, adding the blending slurry into a stirring tank to prepare ore slurry with the mass percentage of 65%, and ensuring that the stirring time is 4 hours; discharging the pulp after size mixing from a stirring tank under the stirring state, screening large-particle minerals by a vibrating screen with the diameter of 0.8mm, conveying the pulp under the screen to a fluidized bed roaster by a pump, controlling the roasting temperature at 700 ℃, supplying oxygen to 80% of the total oxygen required by the complete combustion of the materials, fully ensuring the reduction roasting atmosphere, and reacting for 15 min; the roasted product containing iron directly enters a cooling process, the roasted product containing iron is adjusted to be 20% ore concentration by mass percent, lime is added to adjust the PH value to be 5, the roasted product is conveyed to a magnetic separator, the ore pulp flow is controlled to be 5t/h, the magnetic field intensity is 180mT, iron concentrate containing iron 51% and sulfur 0.3% is produced through magnetic separation, the iron recovery rate is 65.5%, tailings after magnetic separation are common solid waste and are stacked in a tailing pond for storage, and wastewater enters a pulp mixing pond for closed cycle pulp mixing.

Comparative example 2

The water content of the cyanide-containing tailings of an enterprise is 35%, the iron content is 32%, the sulfur content is 2.5%, the tailings are subjected to toxicity leaching, the pH of the overproof components of the leachate is 10.69, the CNT is 158.8mg/L, and the toxic leaching result is dangerous waste. The pyrite mainly contains 43% of sulfur and 39.6% of iron. Under the stirring state, mixing pyrite and cyanogen-containing waste residues according to the ratio of 1:0.8 of the pyrite to the cyanogen-containing waste residues to prepare a mixed solid material containing 20.5% of sulfur, adding the size mixing liquid into a stirring tank to prepare ore pulp with the mass percentage of 65%, and ensuring that the stirring time is 4 hours; discharging the pulp after size mixing from a stirring tank under the stirring state, screening large-particle minerals by a vibrating screen with the diameter of 0.8mm, conveying the pulp under the screen to a fluidized bed roaster by a pump, controlling the roasting temperature at 600 ℃, supplying oxygen to 80% of the total oxygen required by the complete combustion of the materials, fully ensuring the reduction roasting atmosphere, and reacting for 15 min; flue gas containing sulfur dioxide, sulfur trioxide, fine-grained mine dust and the like, which is produced by roasting, is subjected to the working procedures of purification, conversion, absorption and the like of the traditional acid making process to produce an industrial sulfuric acid product; directly feeding the iron-containing calcine produced by roasting into a cooling process, adjusting the concentration of the iron-containing calcine to be 20% in percentage mass ratio, adding lime to adjust the pH value to be 5, conveying the iron-containing calcine to a magnetic separator, controlling the flow rate of ore pulp to be 5t/h and the magnetic field intensity to be 180mT, producing iron ore concentrate containing 51% of iron and 0.29% of sulfur through magnetic separation, wherein the iron recovery rate is 66.5%, tailings after the magnetic separation are common solid waste, piling the solid waste into a tailing pond for storage, and feeding wastewater into a pulp mixing pond for closed-loop circulation pulp mixing.

Comparative example 3

The water content of the cyanide-containing tailings of an enterprise is 35%, the iron content is 32%, the sulfur content is 2.5%, the tailings are subjected to toxicity leaching, the pH of the overproof components of the leachate is 10.69, the CNT is 158.8mg/L, and the toxic leaching result is dangerous waste. The pyrite mainly contains 43% of sulfur and 39.6% of iron. Under the stirring state, mixing pyrite and cyanogen-containing waste residues according to the ratio of 1:0.8 of the pyrite to the cyanogen-containing waste residues to prepare a mixed solid material containing 20.5% of sulfur, adding the size mixing liquid into a stirring tank to prepare ore pulp with the mass percentage of 65%, and ensuring that the stirring time is 4 hours; discharging the pulp after size mixing from a stirring tank under the stirring state, screening large-particle minerals by a vibrating screen with the diameter of 0.8mm, conveying the pulp under the screen to a fluidized bed roaster by a pump, controlling the roasting temperature at 900 ℃, supplying oxygen to 80% of the total oxygen required by the complete combustion of the materials, fully ensuring the reduction roasting atmosphere, and reacting for 15 min; flue gas containing sulfur dioxide, sulfur trioxide, fine-grained mine dust and the like, which is produced by roasting, is subjected to the working procedures of purification, conversion, absorption and the like of the traditional acid making process to produce an industrial sulfuric acid product; the roasted product containing iron directly enters a cooling process, the roasted product containing iron is adjusted to be 20% ore concentration by mass percent, lime is added to adjust the PH value to be 5, the roasted product is conveyed to a magnetic separator, the ore pulp flow is controlled to be 5t/h, the magnetic field intensity is 180mT, iron concentrate containing 52% of iron and 0.28% of sulfur is produced through magnetic separation, the iron recovery rate is 67.5%, tailings after magnetic separation are common solid waste and are stacked in a tailing pond for storage, and wastewater enters a pulp mixing pond for closed cycle pulp mixing.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, but rather as the subject matter of the invention is to be construed in all aspects and as broadly as possible, and all changes, equivalents and modifications that fall within the true spirit and scope of the invention are therefore intended to be embraced therein.