A combined inhibitor for copper-cobalt separation and preparation method thereof

Abstract

The present invention belongs to the technical field of mineral processing, and relates to a combined inhibitor for copper-cobalt separation and a preparation method thereof, and in particular to a combined inhibitor for cobalt minerals used in copper-cobalt sulfide ore sorting or copper-cobalt separation. The combined inhibitor comprises calcium oxide, calcium hypochlorite, and potassium ferrate, wherein the addition amount of each component is calculated by mass: 50-60 parts of calcium oxide, 40-50 parts of calcium hypochlorite, and 1-5 parts of potassium ferrate. The combined inhibitor is formulated into an emulsified liquid, and is directly added to the grinding operation, which has a strong inhibitory effect on cobalt minerals, enables efficient separation of copper and cobalt, reduces the cobalt content in the copper concentrate, and thus achieves the purpose of improving the cobalt recovery rate.

Description

Technical Field

[0001] The invention belongs to the technical field of ore dressing, and relates to a combined inhibitor for copper-cobalt separation and a preparation method thereof, in particular to a cobalt mineral combined inhibitor used for copper-cobalt sorting or copper-cobalt separation in copper-cobalt sulfide ores. Background Art

[0002] Cobalt often exists in the form of sulfides and arsenides. The main cobalt-containing minerals are: cobalt-containing pyrite (Fe, Co) S 2 , arsenic cobaltite CoAsS, pyrocobaltite Co 3 S 4 In addition, there is also nickel-cobalt sulfide (NiCo) 3 S 4 、Cobalt-sulfide ore Co 2 QUR 4 wait.

[0003] The reserves of terrestrial cobalt resources are relatively small, mostly associated with copper, nickel, arsenic and pyrite deposits, and there are very few independent cobalt minerals. China's cobalt resources are very scarce, and have the characteristics of concentrated distribution, small deposit scale, low ore grade, many associated minerals, and great difficulty in mining. They are mainly distributed in Gansu, Shandong, Yunnan, Qinghai, Hebei and Shanxi provinces. According to the latest statistics of the United States Geological Survey in 2018, the global terrestrial cobalt resources found are about 2.5×10 7 t, and the reserves are about 7.0×10 6 t, the cobalt resources of five countries including Congo (Kinshasa), Australia, Cuba, the Philippines and Zambia account for more than 80% of the global reserves.

[0004] The vast majority of my country's cobalt resources are associated ores with low grades, with an average grade of only 0.02%; cobalt is mainly recovered as a by-product; cobalt minerals are mainly cobalt pyrite, sulfide nickel cobalt ore, and cobalt nickel pyrite, and their floatability is quite different from that of copper sulfide minerals, making them easy to separate. However, foreign countries are rich in copper and cobalt resources, especially the cobalt reserves in the Democratic Republic of the Congo are nearly 100,000 tons, accounting for more than 70%, with copper grades of 1.39%-4.63% and cobalt grades of 0.11%-0.62%; cobalt minerals contain high levels of arsenic cobalt ore, sulfide cobalt ore, and sulfide copper cobalt ore. These cobalt minerals have good floatability and little difference from the floatability of copper sulfide minerals, so copper and cobalt separation is difficult.

[0005] The present invention is proposed to solve the problem of efficient separation of copper minerals and cobalt minerals with similar floatability. Summary of the invention

[0006] The present invention aims to provide a combined inhibitor for separation of copper and cobalt and a preparation method thereof, wherein the combined inhibitor can enhance the inhibitory effect on cobalt minerals and ensure that copper minerals are not inhibited. The process reduces the cobalt content in the copper concentrate while ensuring the quality and recovery rate of the copper concentrate, thereby improving the recovery rate of cobalt and enabling efficient recovery and utilization of copper and cobalt resources.

[0007] A combined inhibitor for separation of copper and cobalt comprises the following components: calcium oxide, calcium hypochlorite and potassium ferrate; the weight proportions thereof are: 50-60 parts of calcium oxide, 40-50 parts of calcium hypochlorite and 1-5 parts of potassium ferrate.

[0008] A preparation method of a combined inhibitor for copper-cobalt separation comprises the following steps: placing 50-60 parts of calcium oxide, 40-50 parts of calcium hypochlorite, 1-5 parts of potassium ferrate and 200-300 parts of water in a stirring tank and stirring the mixture into an emulsified liquid, thereby obtaining the combined inhibitor for copper-cobalt separation of the present invention.

[0009] Furthermore, all the components are purchased from the market and are environmentally friendly agents; calcium oxide is produced by Shandong Jinan Zimo Chemical Co., Ltd., industrial grade GB quality standard, content>92%; calcium hypochlorite is industrial grade produced by Jinan Shengge Chemical Co., Ltd., content>28%; potassium ferrate is industrial grade produced by Shanghai Haoyu Industry and Trade Co., Ltd., content>98.5%.

[0010] Furthermore, the stirring speed is 20-100 rpm, and the stirring time is 5-15 minutes.

[0011] Working principle of the combined inhibitor of the present invention:

[0012] (1) Calcium oxide is commonly known as lime. Its inhibitory effect is mainly due to three reasons: ① OH - The ions form an insoluble hydrophilic iron hydroxide film on the surface of pyrite, which can also make the effective ingredient of pyrite capture, dixanthate, unstable under high pH conditions. + Ions are electrically attracted and adsorbed on the surface of pyrite with a pH value of more than 6.8. Some of them are difficult to wash off and form a calcium insoluble film, which is not conducive to the interaction between minerals and collectors. Therefore, when lime is used to adjust the pH value, the pH value is about one unit lower than the pH value achieved by using caustic soda or sodium carbonate. ③ Calcium oxide can desorb the collector adsorbed on the surface of pyrite at the beginning stage.

[0013] (2) Inhibitory effect of calcium hypochlorite, ①Ca(ClO) 2 +CO 2 +H 2 O=CaCO 3↓+2HClO, the insoluble calcium carbonate produced covers the surface of the cobalt mineral, enhancing the hydrophilicity and hindering the mineral's adsorption of the collector. ②2HClO=2HCl+O 2 ↑, hypochlorous acid decomposes to produce oxygen,

[0014] RS 2 ]RS 2 +31 / 2O 2 +H 2 O=RS]FeSO 4 +H 2 SO 4 , so that a hydroxide hydrophilic film is formed on the surface of the sulfide, reducing the adsorption amount of the collector.

[0015] (3) Chemical formula for producing oxygen from potassium ferrate: 2KFeO 4 = K 2 FeO 4 +FeO 2 +O 2 ↑, Potassium ferrate has strong oxidizing properties, produces oxygen, and accelerates the oxidation of sulfide surface.

[0016] (4) Synergistic effect: calcium oxide is an alkaline oxide and also has oxidizing properties. Calcium hypochlorite and potassium ferrate are oxidants. The three reagents have similarities and differences. When combined together, the S 2- Ions are easily oxidized by OH - Substitution or oxidation to form SO 4 2- , generating Ca(OH) or CaSO 4 , which enhances the hydrophilicity of the sulfide surface.

[0017] Compared with the prior art, the invention has the following beneficial effects.

[0018] (1) This combined inhibitor: first, enhances the inhibitory effect on cobalt minerals; second, ensures that copper minerals are not inhibited.

[0019] (2) This process reduces the cobalt content in copper concentrate while ensuring the quality and recovery rate of copper concentrate, thereby increasing the recovery rate of cobalt and enabling copper and cobalt resources to be efficiently recovered and utilized. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention discloses a copper-cobalt separation process.

[0021] Figure 2 The process flow and process conditions of Example 1.

[0022] Figure 3 The process flow and process conditions of Example 2. DETAILED DESCRIPTION

[0023] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0024] A combined inhibitor for separation of copper and cobalt comprises the following components: calcium oxide, calcium hypochlorite and potassium ferrate; the weight proportions thereof are: 50-60 parts of calcium oxide, 40-50 parts of calcium hypochlorite and 1-5 parts of potassium ferrate.

[0025] A preparation method of a combined inhibitor for copper-cobalt separation comprises the following steps: placing 50-60 parts of calcium oxide, 40-50 parts of calcium hypochlorite, 1-5 parts of potassium ferrate and 200-300 parts of water into a stirring tank, stirring at a speed of 20-100 rpm for 5-15 minutes to form an emulsified liquid, which is the combined inhibitor for copper-cobalt separation of the present invention.

[0026] Furthermore, all the components are purchased from the market and are environmentally friendly agents; calcium oxide is produced by Shandong Jinan Zimo Chemical Co., Ltd., industrial grade GB quality standard, content>92%; calcium hypochlorite is industrial grade produced by Jinan Shengge Chemical Co., Ltd., content>28%; potassium ferrate is industrial grade produced by Shanghai Haoyu Industry and Trade Co., Ltd., content>98.5%.

[0027] Example 1: Research on the preferential flotation process of a copper-cobalt ore in Africa.

[0028] The preparation method of the combined inhibitor for copper-cobalt separation is as follows: 60 parts of calcium oxide, 40 parts of calcium hypochlorite, and 2 parts of potassium ferrate are stirred for 10 minutes with a stirrer at a speed of 30 rpm to form an emulsified liquid, which is the combined inhibitor for copper-cobalt separation.

[0029] The copper-cobalt ore mainly contains copper, cobalt, nickel, sulfur and iron. Through optical microscope identification of ore light, thin sections and briquette, it was found that the independent mineral of copper is chalcopyrite, with a content of 3.62%; the independent minerals of cobalt are pyrrhotite, pyrrhotite and cobaltite, with contents of 0.23%, 0.08% and 0.02% respectively; the independent mineral of nickel is mainly cobalt nickel pyrrhotite, which is a cobalt-containing mineral with a content of 0.12%; the independent minerals of sulfur are pyrrhotite and pyrite, with contents of 1.43% and 0.45% respectively; in addition, the ore also contains a small amount of anatase, bismuthinite and natural bismuth ore. The non-metallic minerals are mainly carbonate minerals, quartz and biotite, with contents of 30.79%, 26.26% and 24.41% respectively, followed by muscovite, feldspar, amphibole, pyroxene and wollastonite.

[0030] The sample contains 2.15% copper and 0.17% cobalt. This test adopts a full-priority flotation process for the copper-cobalt ore, that is, first suppress cobalt to float copper, and then obtain copper concentrate after one roughing, two scavenging and three concentrating; copper tailings float cobalt, and then obtain cobalt concentrate after one roughing, two scavenging and two concentrating. The closed-circuit test obtained a copper concentrate with a copper content of 29.63% and a copper recovery rate of 92.12%, and a cobalt concentrate with a cobalt content of 5.63% and a cobalt recovery rate of 63.27%. Figure 2 .

[0031] Example 2: Research on flotation technology of a low-cobalt copper sulfide ore in Africa.

[0032] The preparation method of the combined inhibitor for copper-cobalt separation is as follows: 50 parts of calcium oxide, 50 parts of calcium hypochlorite, 3 parts of potassium ferrate and 250 parts of water are stirred for 10 minutes with a stirrer at a speed of 30 rpm to form an emulsified liquid, which is the combined inhibitor for copper-cobalt separation.

[0033] The copper-cobalt ore has many mineral species and complex intercalation relationships. The target recovery elements in the ore are copper and cobalt. The copper mineral is mainly chalcopyrite, with a content of 3.33%, followed by bornite, with a content of 0.11%, and a small amount of chalcocite, blue chalcocite, covellite, etc.; the cobalt mineral is mainly sulfide copper cobaltite, with a content of 0.08%, followed by trace sulfide cobaltite.

[0034] The sample contains 1.25% copper and 0.088% cobalt. Due to the low cobalt content, the copper-cobalt ratio reaches 14 times. The process of copper-cobalt mixed flotation and copper-cobalt separation is adopted. The closed-circuit test results show that the copper concentrate contains 31.52% copper and the copper recovery rate is 92.32%; the cobalt concentrate contains 2.12% cobalt and the cobalt recovery rate is 67.56%. Figure 3 .

Claims

1. A combined inhibitor for copper-cobalt separation, characterized in that: The combined inhibitor comprises the following components: calcium oxide, calcium hypochlorite, and potassium ferrate; the weight proportions thereof are: 50-60 parts of calcium oxide, 40-50 parts of calcium hypochlorite, and 1-5 parts of potassium ferrate; The preparation method of the copper-cobalt separation combined inhibitor is as follows: 50-60 parts of calcium oxide, 40-50 parts of calcium hypochlorite, 1-5 parts of potassium ferrate, and 200-300 parts of water are placed in a stirring tank and stirred into an emulsified liquid to obtain the copper-cobalt separation combined inhibitor; Stirring speed: 20-100 rpm, stirring time: 5-15 minutes.

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