阅读说明：本技术 一种低品位钴矿高效回收钴的方法 (Method for efficiently recovering cobalt from low-grade cobalt ore ) 是由 张兴勋 巫銮东 谭希发 康锦程 叶志勇 张文彬 张日富 罗胜 于 2020-06-28 设计创作，主要内容包括：本发明涉及一种低品位钴矿高效回收钴的方法,采用包括浸出-除铁-除锰-两段沉钴组合工艺佐以自产沉钴渣和二合一氧化剂,得到合格的氢氧化钴,实现了低品位钴矿资源的利用。它具有具有操作简单、适应性强、钴回收率高、氢氧化钴产品质量好、生产成本低、对环境有好、易工业化等优点,可为国内外低品位钴矿的开发提供广阔的空间,适于矿冶行业应用。(The invention relates to a method for efficiently recovering cobalt from low-grade cobalt ores, which adopts a combined process comprising leaching-iron removal-manganese removal-two-stage cobalt precipitation to obtain qualified cobalt hydroxide by assisting self-produced precipitated cobalt slag and a two-in-one oxidant, and realizes the utilization of low-grade cobalt ore resources. The method has the advantages of simple operation, strong adaptability, high cobalt recovery rate, good cobalt hydroxide product quality, low production cost, good environment, easy industrialization and the like, can provide wide space for the development of low-grade cobalt ores at home and abroad, and is suitable for the application in the mining and metallurgy industry.)

1. A method for efficiently recovering cobalt from low-grade cobalt ore is characterized in that a combined process comprising leaching, iron removal, manganese removal and two-stage cobalt precipitation is adopted to obtain qualified cobalt hydroxide together with self-produced precipitated cobalt slag and a two-in-one oxidant, so that the utilization of low-grade cobalt ore resources is realized.

2. The method as claimed in claim 2, which includes the following process steps and conditions in the following order:

(1) leaching: firstly, using low grade cobalt ore which is milled to-0.074 mm and has 65-90% of particles as leached ore, supplementing subsequent neutralization slag as leached ore after the system runs stably, adding water or supernatant liquor of a subsequent slag pulp library to adjust to ore pulp with the concentration of 20-35%, then adding concentrated sulfuric acid and a reducing agent to leach, controlling the mass concentration of sulfuric acid in the leaching process to be 8-15 g/L and the oxidation-reduction potential to be 330-400 mv, reacting for 300-420 min, finishing solid-liquid separation after the reaction to obtain cobalt-containing solution 1 and leached slag, and sending the leached slag to a slag pulp library for stockpiling;

(2) iron removal: under the conditions of air-filled iron removal reaction for 20-40 min and end-point pH value control of 4.0-4.5, directly using a cobalt-containing liquid 1 at the beginning, supplementing subsequent two-stage cobalt deposition slag after the system runs stably, and performing solid-liquid separation after the reaction is finished to obtain a cobalt-containing liquid 2 and neutralized slag;

(3) removing manganese: adding an oxidant into the cobalt-containing liquid 2, controlling the oxidation-reduction potential to be 1000-1250 mv, carrying out a demanganization reaction for 60-120 min, carrying out solid-liquid separation after the reaction is finished, obtaining a cobalt-containing liquid 3 and demanganization slag, and conveying the demanganization slag to a slag slurry warehouse for stockpiling;

(4) two-stage cobalt precipitation:

firstly, precipitating cobalt, adding magnesium oxide with the concentration of 5-15% into a cobalt-containing solution 3, controlling the pH value to be 7.90-8.15, precipitating cobalt for reaction for 240-300 min, and carrying out solid-liquid separation after the reaction is finished to obtain a cobalt hydroxide product and a cobalt precipitation solution 1;

and (3) second-stage cobalt precipitation: adding lime milk into the cobalt precipitation solution 1, controlling the pH value to be 8.40-8.60, continuing cobalt precipitation reaction for 60-120 min, performing solid-liquid separation after the reaction is finished to obtain second-stage cobalt precipitation slag and cobalt precipitation solution 2, and discharging the cobalt precipitation solution 2 after the cobalt precipitation solution 2 is treated to reach the standard.

3. The method as set forth in claim 2, wherein the oxidizing agent for manganese removal in step (3) is oxidizing agent A plus oxidizing agent B, and the molar ratio of oxidizing agent A: oxidant B ═ 1: 1-3.

4. The method as set forth in claim 3, wherein said oxidizing agent A is composed of two elements of hydrogen and oxygen.

5. The method as set forth in claim 3, wherein said oxidizing agent B is composed of three elements of hydrogen, oxygen and sulfur.

6. The method as set forth in claim 2, characterized in that the magnesium oxide for cobalt precipitation in the two stages of step (4) is subjected to discontinuous milk production to increase activity, and the milk production is carried out once every 15-25 min, wherein the milk production time is 3-5 min each time.

7. The method as set forth in claim 2, characterized in that said leaching in step (1) uses a reducing agent selected from the group consisting of sodium sulfite, sodium metabisulfite, sulfur dioxide and sulfide.

8. The method as claimed in claim 2, 3 or 7, wherein the leached slag leached in the step (1) and the supernatant of the manganese-removed slag heap residue slurry storage in the step (3) are returned to the step (1) for leaching together, so that the use amount of concentrated sulfuric acid and a reducing agent can be reduced.

9. The method according to claim 1 or 2, wherein the low-grade cobalt ore raw ore contains 0.2-0.5% of cobalt, less than 0.5% of copper and 5-20% of alkaline gangue.

Technical Field

The invention relates to a method for efficiently recovering cobalt from low-grade cobalt ore, which is suitable for the application of the mining and metallurgy industry.

Background

Cobalt is an important material for manufacturing high-temperature-resistant alloy, hard alloy, catalyst, new energy automobile battery and ferromagnetic material, one of important strategic mineral resources in the world is found to be about 2500 million tons and 720 million tons in the global resource amount by 2016 years, wherein the sum of the reserves of Congo (gold), Australia and Cuba 3 countries accounts for 69.4% of the world, and particularly the reserve of the cobalt of Congo (gold) is up to 340 million tons and is the first place in the world. The reserves of Chinese cobalt resources are only 8 ten thousand tons, which account for 1.1 percent of the reserves of the whole world. From the basic law of mineral resource consumption, the demand of cobalt will continuously rise, and the restriction of resource shortage situation will continuously increase. At present, many cobalt ores at home and abroad enter the later period of exploitation, the resources of rich ores and easily-selected ores are nearly exhausted, but a large amount of low-grade cobalt ore resources are not developed and utilized, so how to efficiently and economically develop and utilize the low-grade cobalt ore resources has very important significance for relieving the outstanding contradiction between supply and demand of high-quality cobalt ores and improving the guarantee period of the cobalt ore resources.

In recent years, domestic and foreign scholars have made many studies on cobalt recovery from cobalt ore and have achieved stage results. For example, chinese patent CN101760616B discloses a "leaching method of cobalt-containing ore", which comprises the following steps: A) mixing the cobalt-containing ore with a sulfuric acid solution to carry out sulfuric acid leaching to obtain a leaching solution containing cobalt sulfate; B) purifying the leaching solution to obtain a cobalt sulfate solution; C) mixing the cobalt sulfate solution with calcium oxide and/or calcium hydroxide and calcium sulfate serving as seed crystals to generate calcium sulfate precipitate and cobalt hydroxide precipitate; and D) separating the calcium sulfate and the cobalt hydroxide, wherein the method has the defects of complicated separation process of the calcium sulfate and the cobalt hydroxide, low cobalt recovery rate and the like; chinese patent CN101921914B discloses an iron removal process for copper-cobalt ore leaching solution, which comprises the steps of firstly carrying out oxidation treatment on the solution before iron removal to oxidize bivalent iron in the solution into trivalent iron; then removing most iron impurities in the oxidized liquid before iron removal in an iron removal tank by using a goethite method, removing residual iron and other metal impurities in the solution by using a neutralization precipitation iron removal method, and filter-pressing the obtained ore pulp by using a filter press, wherein the filtrate is the liquid after iron removal, and the method has the defects of long iron removal process flow, large iron removal agent consumption, high cost and the like; chinese patent CN104726701B discloses a method for leaching valuable metals from heterogenite, which comprises the following steps: crushing the heterogenite to more than or equal to 200 meshes, adding a carbonaceous reducing agent accounting for 1-30% of the heterogenite in mass, and uniformly mixing; dehydrating and roasting at 300-700 ℃ in a closed state; adding a leaching agent into the roasted and cooled material, introducing high-pressure gas for leaching, heating and controlling the temperature to be 80-150 ℃ for leaching, wherein the method has the defects of large equipment investment, high energy consumption, high production cost and the like. The search of the inventor does not find a report about a method for efficiently recovering cobalt from low-grade cobalt ores.

With the increasingly reduced global mineral resource amount and the inherent defects of the existing low-grade cobalt ore processing technology, the method for efficiently recovering cobalt from low-grade cobalt ore is urgent and has great significance.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for efficiently recovering cobalt from low-grade cobalt ores, which can efficiently recover the cobalt in the low-grade cobalt ores, can reduce the recovery cost, is easy to implement and provides wide space and technical support for development of the low-grade cobalt ores.

The task of the invention is completed by the following technical scheme:

a method for efficiently recovering cobalt from low-grade cobalt ore adopts a combined process comprising leaching-deironing-demanganizing-two-stage cobalt precipitation to obtain qualified cobalt hydroxide together with self-produced precipitated cobalt slag and a two-in-one oxidant, thereby realizing the utilization of low-grade cobalt ore resources.

The percentages referred to in the specification are mass percentages.

Compared with the prior art, the invention has the following advantages or effects:

(1) the two-stage precipitated cobalt slag and the finely ground low-grade cobalt ore are combined for removing iron, so that the cost of an iron removing agent is saved, cobalt in the two-stage precipitated cobalt slag is recovered, and most of carbonic acid in the finely ground low-grade cobalt ore is consumed in advance by the other party, so that the dosage of sulfuric acid is greatly reduced when the iron removing neutralization slag returns to the first step for leaching cobalt.

(2) The special oxidant for removing manganese is adopted, so that the method is green and environment-friendly, has high manganese removal efficiency, and does not add other impurities which influence the quality of a cobalt hydroxide product to the manganese removal solution.

(3) The production line formed by the method has the advantages of simple operation, strong adaptability, high cobalt recovery rate, good cobalt hydroxide product quality, low production cost, good environment and easy industrialization, and can provide wide space for the development of low-grade cobalt ores at home and abroad.

Drawings

Fig. 1 is a process flow diagram of a method for efficiently recovering cobalt from low-grade cobalt ore according to the invention.

The description is described in further detail below with reference to the accompanying drawings.

Detailed Description

As shown in figure 1, the method for efficiently recovering cobalt from low-grade cobalt ore adopts a combined process comprising leaching-deironing-demanganizing-two-stage cobalt precipitation to obtain qualified cobalt hydroxide together with self-produced precipitated cobalt slag and a two-in-one oxidant, thereby realizing the utilization of low-grade cobalt ore resources.

The process of the invention may further be:

the method specifically comprises the following sequential process steps and conditions:

(1) leaching: firstly, using low grade cobalt ore which is milled to-0.074 mm and has 65-90% of particles as leached ore, supplementing subsequent neutralization slag as leached ore after the system runs stably, adding water or supernatant liquor of a subsequent slag pulp library to adjust to ore pulp with the concentration of 20-35%, then adding concentrated sulfuric acid and a reducing agent to leach, controlling the mass concentration of sulfuric acid in the leaching process to be 8-15 g/L and the oxidation-reduction potential to be 330-400 mv, reacting for 300-420 min, finishing solid-liquid separation after the reaction to obtain cobalt-containing solution 1 and leached slag, and sending the leached slag to a slag pulp library for stockpiling;

(2) iron removal: under the conditions of air-filled iron removal reaction for 20-40 min and end-point pH value control of 4.0-4.5, directly using a cobalt-containing liquid 1 at the beginning, supplementing subsequent two-stage cobalt deposition slag after the system runs stably, and performing solid-liquid separation after the reaction is finished to obtain a cobalt-containing liquid 2 and neutralized slag;

(3) removing manganese: adding an oxidant into the cobalt-containing liquid 2, controlling the oxidation-reduction potential to be 1000-1250 mv, carrying out a demanganization reaction for 60-120 min, carrying out solid-liquid separation after the reaction is finished, obtaining a cobalt-containing liquid 3 and demanganization slag, and conveying the demanganization slag to a slag slurry warehouse for stockpiling;

(4) two-stage cobalt precipitation:

firstly, precipitating cobalt, adding magnesium oxide with the concentration of 5-15% into a cobalt-containing solution 3, controlling the pH value to be 7.90-8.15, precipitating cobalt for reaction for 240-300 min, and carrying out solid-liquid separation after the reaction is finished to obtain a cobalt hydroxide product and a cobalt precipitation solution 1;

and (3) second-stage cobalt precipitation: adding lime milk into the cobalt precipitation solution 1, controlling the pH value to be 8.40-8.60, continuing cobalt precipitation reaction for 60-120 min, performing solid-liquid separation after the reaction is finished to obtain second-stage cobalt precipitation slag and cobalt precipitation solution 2, and discharging the cobalt precipitation solution 2 after the cobalt precipitation solution 2 is treated to reach the standard;

the oxidant for removing manganese in the step (3) is an oxidant A and an oxidant B, and the molar ratio of the oxidant A: oxidant B ═ 1: 1-3.

The oxidant A consists of two elements of hydrogen and oxygen.

The oxidant B consists of three elements of hydrogen, oxygen and sulfur.

And (4) discontinuously preparing milk by using magnesium oxide for cobalt precipitation in the two sections in the step (4) to increase the activity, wherein the milk is prepared every 15-25 min, and the milk preparation time is 3-5 min each time.

The reducing agent for leaching in the step (1) is any one of sodium sulfite, sodium metabisulfite, sulfur dioxide and sulfide.

And (3) returning the leached slag leached in the step (1) and the supernatant of the manganese-removed slag stacking slag slurry library subjected to manganese removal in the step (3) to the step (1) for leaching together, so that the use amounts of concentrated sulfuric acid and a reducing agent can be reduced.

The low-grade cobalt ore raw ore contains 0.2-0.5% of cobalt, less than 0.5% of copper and 5-20% of alkaline gangue.

The following examples are provided to further verify and illustrate the processes and effects of the present invention, and should not be construed as limiting the scope of the present invention, and the process flow adopted in the examples is shown in fig. 1.