Process for extracting nickel and molybdenum from black shale by acid wet method
阅读说明：本技术 一种酸性湿法从黑色页岩中提取镍钼的工艺 (Process for extracting nickel and molybdenum from black shale by acid wet method ) 是由 秦纯 刘汉瑛 冉茂情 于 2021-03-05 设计创作，主要内容包括：一种酸性湿法从黑色页岩中提取镍钼的工艺,包括以下步骤：1)将黑色页岩粉碎后加入到水中；2)在搅拌的条件下将溶液温度升高到80-100℃,然后往其中通入工业氧气；然后泵入浓硝酸；3)过滤得到过滤液,过滤液通过离子交换塔得到淋洗液和穿塔液；4)将步骤3)得到的淋洗液用氨水调节pH值,并且升温到80-120℃,过滤得到NiSO-4溶液；5)将步骤3)得到的穿塔液用NaOH溶液调节pH值至5～6；然后用氨水调整pH值至7-8,升温到80-100℃,然后除杂；过滤并洗涤后得到钼酸铵溶液。在本发明中,在浓硝酸的作用下,黑色页岩中的硫会从中脱离,然后被氧化成硫酸,这样就解决了传统工艺中二氧化硫污染空气的问题。(A process for extracting nickel and molybdenum from black shale by an acid wet method comprises the following steps: 1) crushing black shale and adding the crushed black shale into water; 2) raising the temperature of the solution to 80-100 ℃ under the condition of stirring, and then introducing industrial oxygen into the solution; then pumping concentrated nitric acid; 3) filtering to obtain filtrate, and passing the filtrate through an ion exchange tower to obtain leacheate and tower-penetrating liquid; 4) adjusting the pH value of the leacheate obtained in the step 3) by using ammonia water, heating to 80-120 ℃, and filtering to obtain NiSO 4 A solution; 5) regulating the pH value of the tower penetrating liquid obtained in the step 3) to 5-6 by using a NaOH solution; then adjusting the pH value to 7-8 by ammonia water, heating to 80-100 ℃, and then removing impurities; filtering and washing to obtain the ammonium molybdate solution. In the invention, under the action of concentrated nitric acid, sulfur in the black shale can be separated from the black shale and then oxidized into sulfuric acid, thus solving the problem that the sulfur dioxide pollutes the air in the traditional process.)
1. A process for extracting nickel and molybdenum from black shale by an acid wet method is characterized by comprising the following steps: 1) crushing black shale, adding the crushed black shale into water, and uniformly stirring; the solid-liquid ratio is 1: 1;
2) raising the temperature of the solution obtained in the step 1) to 80-100 ℃ under the condition of stirring, and then introducing excessive industrial oxygen into the solution; pumping concentrated nitric acid at the pumping speed of 200-300 mL/h, adjusting the pH value to 0-0.5, and keeping the pH value for more than 1 hour;
3) filtering the solution obtained in the step 2) to obtain filtrate, and treating the filtrate in an ion exchange tower to obtain leacheate and tower-through liquid, wherein the leacheate is a concentrated cation group and the liquid is a concentrated anion group;
4) adjusting the pH value of the leacheate obtained in the step 3) to 2-4 by using ammonia water, heating to 80-120 ℃, preserving heat for more than one hour, and filtering to obtain NiSO4A solution;
5) regulating the pH value of the tower penetrating liquid obtained in the step 3) to 5-6 by using a NaOH solution; then ammonia water is used for adjusting the pH value to 7-8, after the mixture is kept stand for more than twenty minutes, the temperature is raised to 80-100 ℃, and MgCl is added2Then NH is added4Cl until no precipitate is formed; filtering and washing to obtain the ammonium molybdate solution.
2. The process for extracting nickel and molybdenum from black shale according to the acid wet method of claim 1, wherein the acid wet method comprises the following steps: introducing excessive industrial oxygen all the time in the step 2).
3. The process for extracting nickel and molybdenum from black shale according to the acid wet method of claim 1, wherein the acid wet method comprises the following steps: the particle size of the black shale particles crushed in the step 1) is smaller than the corresponding particle size of 100 meshes.
4. The process for extracting nickel and molybdenum from black shale according to the acid wet method of claim 1, wherein the acid wet method comprises the following steps: and (3) adding a washing liquid obtained by carrying out secondary washing on the residue in the step 3) into the step 1) or the step 2).
5. The process for extracting nickel and molybdenum from black shale according to the acid wet method of claim 1, wherein the acid wet method comprises the following steps: MgCl added in the step 5)2The amount of (a) is one time the weight of P, AS and S in the black shale; addition of NH4The amount of Cl is MgCl2Half of the amount.
6. The process for extracting nickel and molybdenum from black shale according to the acid wet method of claim 1, wherein the acid wet method comprises the following steps: and (3) washing the residue obtained by filtering in the step 3) to obtain a washing liquid, and treating the washing liquid and the filtering liquid in an ion exchange tower.
Technical Field
The invention relates to a metal mineral extraction technology, in particular to a process for extracting nickel and molybdenum from black shale by an acid wet method.
Background
In large-area hilly lands in southwest provinces of China, abundant black shale layers are stored, although the black shale layers are stored dispersedly, the economic value generated by centralizing all the quantity in China is probably not inferior to that of the centrally stored vanadium titano-magnetite, and the economic value is relatively high. Based on the above general knowledge, enterprises for smelting black shale and extracting nickel and molybdenum are created in succession in areas such as Hunan West and Guizhou Zunyi from the end of the last century to the short decade of the century. The technology disclosed by the technology has the following characteristics that the process flow is simple, the produced products are ammonium molybdate and high-grade molybdenum concentrate, the recovery rates of molybdenum and nickel are high, and the technology is well received by users. However, the process has the defects of two-stage high-temperature roasting, and particularly, a large amount of sulfur dioxide flue gas generated by the first-stage desulfurization roasting is difficult to treat, so that the economic pressure is huge and the further treatment of the product is extremely difficult. The major defect influences the mining of the black shale, causes disasters of the whole industry, and even stops the whole industry till now. The motivation of the invention is to abolish the desulfurization roasting to solve the problem of influencing the social ecology. The improvement of society brings the hope that the all-industry rotary machine brings the rotary machine to the whole enterprise of black shale development.
Disclosure of Invention
The technical problem to be solved by the invention is to overcome the defects of the prior art and provide a process for extracting nickel and molybdenum from black shale by an acid wet method, which solves the problem of environmental pollution caused by sulfur dioxide in the traditional process.
In order to solve the technical problems, the technical scheme provided by the invention is as follows: a process for extracting nickel and molybdenum from black shale by an acid wet method comprises the following steps: 1) crushing black shale, adding the crushed black shale into water, and uniformly stirring; the solid-liquid ratio is 1: 1;
2) raising the temperature of the solution obtained in the step 1) to 80-100 ℃ under the condition of stirring, and then introducing excessive industrial oxygen into the solution; pumping concentrated nitric acid at the pumping speed of 200-300 mL/h, adding a proper amount of water during the pumping of the nitric acid, adjusting the pH value to 0-0.5, and keeping the pH value for more than 1 hour;
3) filtering the solution obtained in the step 2) to obtain filtrate, and treating the filtrate in an ion exchange tower to obtain leacheate and tower-through liquid, wherein the leacheate is a concentrated cation group and the liquid is a concentrated anion group;
4) adjusting the pH value of the leacheate obtained in the step 3) to 2-4 by using ammonia water, heating to 80-120 ℃, preserving heat for more than one hour, and filtering to obtain NiSO4A solution;
5) regulating the pH value of the tower penetrating liquid obtained in the step 3) to 5-6 by using a NaOH solution; then ammonia water is used for adjusting the pH value to 7-8, after the mixture is kept stand for more than twenty minutes, the temperature is raised to 80-100 ℃, and MgCl is added2Then NH is added4Cl until no precipitate is formed; filtering and washing to obtain the ammonium molybdate solution.
In the invention, excess industrial oxygen is always introduced during the step 2).
In the invention, the particle sizes of the black shale particles crushed in the step 1) are all smaller than the particle size corresponding to 100 meshes.
In the present invention, the washing liquid obtained by the secondary washing of the residue in the step 3) is added to the step 1) or the step 2).
In the present invention, MgCl added in said step 5) is used2The amount of (a) is one time the weight of P, AS and S in the black shale; addition of NH4The amount of Cl is MgCl2Half of the amount.
In the present invention, the washing liquid obtained by washing the residue obtained by the filtration in the step 3) is treated in an ion exchange column together with the filtrate.
Compared with the prior art, the invention has the advantages that: in the invention, under the action of trace nitric acid, sulfur in the black shale can be separated from the black shale, and then the black shale is oxidized into sulfuric acid under the action of oxygen, so that the problem that sulfur dioxide pollutes air in the traditional process is solved.
Drawings
Fig. 1 is a process flow diagram of a process for extracting nickel and molybdenum from black shale by an acid wet method in example 1.
Detailed Description
In order to facilitate an understanding of the present invention, the present invention will be described more fully and in detail with reference to the preferred embodiments, but the scope of the present invention is not limited to the specific embodiments described below.
Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.
A process for extracting nickel and molybdenum from black shale by an acid wet method comprises the following steps: 1) crushing black shale to ensure that the particle sizes of the particles of the black shale are smaller than the particle sizes corresponding to 100 meshes, then adding the crushed black shale into water, and uniformly stirring the mixture; the solid-liquid ratio is 1: 1;
2) raising the temperature of the solution obtained in the step 1) to 80-100 ℃ under the condition of stirring, and then introducing excessive industrial oxygen into the solution; pumping concentrated nitric acid at the pumping speed of 200-300 mL/h, adding a proper amount of water during the pumping of the nitric acid, adjusting the pH value to 0-0.5, and keeping the pH value for more than 1 hour; and (3) introducing industrial oxygen all the time in the whole process of the step 2), after the concentrated nitric acid is added and pumped, because the reaction is violent, the temperature in the system, the gaseous foam and the liquid level of the system can be changed violently, when the reaction is too violent, a proper amount of water is added to cool the reaction, and meanwhile, the introduction amount of the industrial oxygen can be increased. In this example, the amount of nitric acid pumped is actually controlled by the pH. From another perspective, it is believed that concentrated nitric acid acts as an initiating element in the acidic wet conversion.
3) Filtering the solution obtained in the step 2) to obtain filtrate, and treating the filtrate and washing liquid obtained by washing the obtained residues in an ion exchange tower together to obtain leaching liquid integrated with cation groups and tower-through liquid integrated with anion groups; in the present invention, the washing liquid obtained by the secondary washing of the residue may be added to step 1) or step 2).
4) Adjusting the pH value of the leacheate obtained in the step 3) to 2-4 by using ammonia water, heating to 80-120 ℃, preserving heat for more than one hour, and filtering to obtain NiSO4A solution;
5) regulating the pH value of the tower penetrating liquid obtained in the step 3) to 5-6 by using a NaOH solution; then ammonia water is used for adjusting the pH value to 7-8, after the mixture is kept stand for more than twenty minutes, the temperature is raised to 80-100 ℃, and MgCl is added2Then NH is added4Cl until no precipitate is formed; filtering and washing to obtain the ammonium molybdate solution. MgCl added in step 5)2The amount of (a) is one time the weight of P, AS and S in the black shale; addition of NH4The amount of Cl is MgCl2Half of the amount. That is, the amount of P, AS and S in the black shale needs to be detected in advance
Example 1
The embodiment provides a process for extracting nickel and molybdenum from black shale by an acid wet method.
1) Preparing: raw materials: 100 kg of black shale concentrate, and the components: the Mo content is about 5 percent, and the Ni content is about 2.5 percent. In this embodiment, the black shale has a particle size of 100 meshes or more, that is, the particle size of the black shale is smaller than the particle size corresponding to 100 meshes.
2) Wet conversion: adding 100L of water into a container, heating the container to 80-10 ℃ under the condition of stirring, slowly feeding excess industrial oxygen into the container, indicating the height change of the liquid level in the container at the moment, and ensuring that the liquid-solid ratio (volume: weight) is 1: 1. finally pumping concentrated nitric acid into the system, wherein the pumping speed is 200-300 mL/h; at the moment, the temperature, the gaseous foam and the liquid line position in the system are changed greatly, water is added at any time, the pH value is regulated and controlled to be gradually reduced from neutral to between pH0 and 0.5, and the pH value is kept for about 2 hours. To complete the wet conversion stage of the process.
Then, the conversion product is filtered, washed and treated by a cation resin exchange tower to obtain an eluent a integrating the cation groups and a tower-through liquid b for treating the anion groups, and the two parts are respectively placed in an impurity removal groove a and an impurity removal groove b for treatment. The heating value of the filter residue obtained after filtration is higher, and the filter residue can be used as fuel of a power plant.
Treating in a tank A: firstly, diluting the rinsing clean liquid to 100L by using clean water, adjusting the pH value to 3.0 by using ammonia water, then heating and blowing to 100 ℃, and keeping the constant value of the pH value for more than 1 hour so as to completely separate out impurities mainly containing Fe. Filtering and washing to obtain clean NiSO4Concentrating the solution. The concentration step contains two contents: firstly, strong acid cation resin is used for adsorbing the eluent with the concentration of more than 80g/L of Ni, then the eluent is heated and evaporated until the net liquid with the concentration of 120g/L of Ni, and then the product is cooled and crystallized, thus obtaining 6.06 kg of nickel sulfate product.
B, treatment of the groove: firstly diluting the tower penetrating liquid of the tank b to 100L, roughly adjusting the pH to 5-6 by using NaOH solution with the concentration of 2mol/L under the condition of stirring, finely adjusting the pH to 7-8 by adding ammonia water, then stabilizing for half an hour, heating the system to 80-100 ℃, adding MgCL, and2 40 kg, then NH is added4CL20 kg slave plus NH4Cl initially a substantial deposit formation was found. After addition, a small sample is taken and MgCl is added2And NH4And checking by Cl to ensure that no new deposit is generated. And (3) proving that: and correspondingly, removing acid impurities such as sulfur, phosphorus, arsenic and the like, filtering and washing to obtain a clean solution, and concentrating. The operation is divided into two steps, wherein firstly, strong base resin is used for concentrating the leaching solution to obtain leacheate, the concentration of Mo reaches 60g/L, then the leaching solution is switched to the second step of evaporation concentration, and then the leaching solution is slightly evaporated to obtain [ Mo ]]Reaching 80 g/L. And finally, performing acid precipitation by using HCl with the concentration of 2N, and drying the precipitate to obtain 8.7kg of ammonium molybdate product.
In this example, the filter residue produced after the treatment in tank A and tank B can be used as backfill material for the pit.
In the embodiment, on the premise of ensuring the recovery rate of nickel and molybdenum; in the embodiment, under the action of trace nitric acid, sulfur in the black shale can be separated from the black shale, and then the black shale is oxidized into sulfuric acid under the action of oxygen, so that the problem that sulfur dioxide pollutes air in the traditional process is solved.