Sodium sulfide is a strong base weak acid salt. As flotation adjusting agent, which other lead ore, sphalerite, yellow copper ore, bismuthinite was inhibited. For example, in the separation of copper- molybdenum mixed concentrate and the separation of molybdenum-niobium mixed concentrate, Na 2 S-prevented copper molybdenum and antimony molybdenum are used. But the use of Na 2 S suppression achieved Ni 3 S 2 and Ni 3 S 2 Cu 2 S flotation separation has not been reported. In this paper, pure minerals, artificial mixed minerals and high-ice nickel were used to test the pH of the slurry, Na 2 S and Na 2 S+ZnS0 4 as inhibitors to inhibit the flotation behavior of Ni 3 S 2 . Na 2 S has a strong inhibitory effect on Ni 3 S 2 in the dosage range, and can effectively separate Ni 3 S 2 and Cu 2 S. 1. Samples, reagents and experimental methods (a) sample Hexagonal sulfur nickel ore and chalcocite are taken from Jinchuan Nonferrous Metals Company second smelter. Ni 3 S 2 is an anode product of nickel concentrate after refining in a reverberatory furnace. After crushing, porcelain ball milling and magnetic separation, the alloy is prepared to have a particle size of -74 μm. Cu 2 S is a high-ice nickel flotation copper concentrate. After mechanical scrubbing, acetone extraction, and hydrochloric acid washing, a sample having a particle size of -74 μm was prepared and stored in a desiccator for use. The multi-element analysis results were (%): hexagonal sulfur nickel ore: Ni 67.33, Cu 3.72, Fe 1.66, S 20.75; chalcopyrite: Ni 1.37, Cu 70.17, Fe 4.53, S 22.59. (2) Pharmacy Sodium sulfide is produced in Bayi Chemical Plant, Nanxian County, Hunan Province. Zinc Sulfate is produced from Guangzhou Chemical Reagent Factory. The collectors used in the test, butyl sodium xanthate and ethyl sodium xanthate, were produced from Shandong Qixia Concentrate Pharmaceutical Factory and were also analytically pure. The pH adjuster sodium hydroxide is an analytically pure reagent. The test water is one distilled water. (3) Test methods The single mineral test and the artificial mixed mineral flotation separation test were carried out in a hanging trough flotation machine having a volume of 40 m1. The ore sample was ultrasonicated for 5 min before flotation. The amount of mineral sample was 2g per test and flotation was carried out for 4 minutes. The flotation test of high ice nickel was carried out in a 1 liter and 0.5 liter single tank flotation machine. Each test sample was 350 g, and the flotation was carried out according to the procedure of stirring→pH adjuster→inhibitor→collector→foaming agent. Second, test results and discussion (I) Effect of Na 2 S dosage on mineral flotation performance Sodium sulfide is a strong base weak acid salt, easily soluble in water and hydrolyzed, forming S 2- , HS - , OH - and the like in water. It inhibits many sulfide minerals, such as chalcopyrite and stibnite. However, there is no report on the inhibition behavior of Na 2 S on Ni 3 S 2 flotation in high ice nickel. In this paper, the inhibition performance of Ni 2 S dosage on Ni 3 S 2 flotation in high ice nickel was studied. Figure 1 is a graph showing the relationship between the amount of Na 2 S and the floatability of minerals (the total amount of butyl xanthate and ethyl yellow is 10 -4 mol/l, the ratio is 1..1). It can be seen from the figure that the effect of Na 2 S on the flotation performance of Ni 3 S 2 is related to the amount. When the amount of Na 2 S is 1.0～2.O×10 -4 mol/l, there is a certain activation effect on the flotation of Ni 3 S 2 . When the amount is more than 2.O×10 -4 mol/l, Ni 3 S 2 Flotation began to be inhibited. When the dosage reached 5.0×10 -4 mol/l, the floatability of Ni 3 S 2 was basically inhibited. In this range of use, the floatability of Cu 2 S flotation is not substantially affected. (2) Effect of pH on the floatability of minerals in the presence of Na 2 S It can be seen from Fig. 2 (Na 2 S concentration 4×10 -4 mol/l, butyl xanthate and ethyl yellow medicinal amount 10 -4 mol/l), and the floatability of minerals in the presence of Na 2 S It is closely related to pH. Ni 3 S 2 flotation is difficult to suppress in the range of pH 7-10. When the pH of the medium is >10, the flotation of Ni 3 S 2 is easily inhibited by Na 2 S. When the pH of the medium reaches about 11.5, Ni 3 S 2 basically loses buoyancy; while Cu 2 S flotation has better floatability over the entire pH range of the medium at the indicated NNa 2 S dosage. Even if the pH of the medium reaches 12.5, there is still a high floating rate. (III) Effect on the floatability of minerals when Na 2 S is mixed with ZnSO 4 It can be seen from Figure 3 (Na 2 S dosage 4×10 -4 mol/l, butyl xanthate and ethyl yellow dosage 10-4 mol/l), when Na 2 S is present, with the amount of ZnSO 4 Increasing, the floatability of Ni 3 S 2 decreases rapidly. When the amount of ZnSO 4 is 4×10 -4 mol/l and the amount of Na 2 S is also 4×10 -4 mol/l, Ni 3 S 2 flotation Basically, the floatability is lost. Comparing Fig. 1 and Fig. 3, it can be seen that the mixing of Na 2 S and ZnSO 4 has a stronger inhibitory effect, while the floatability of Cu 2 S is only slightly decreased. (4) Separation test of artificial mixed mineral flotation The artificial mixed mineral flotation separation test was carried out on the basis of single mineral flotation test. The artificial mixed mineral is a chalcopyrite: hexagonal sulphur nickel ore = 1:2. It contains 25.87% Cu and 45.34% Ni. The sorting test procedure and the pharmaceutical system used are shown in Figure 4, and the results are shown in Table 1. Table 1 Results of artificial mixed mineral flotation separation test condition pH=10 pH=11 pH=12 Cu Ni Cu Ni Cu Ni Product name and content (%) Copper concentrate 68.52 4.40 69.55 3.44 69.71 3.38 Nickel concentrate 3.20 67.36 2.63 67.33 2.66 67.54 The sum of each other 7.60 6.07 6.04 It can be seen from Table 1 that the pulp has a pH of 11.0, Na 2 S and ZnS 4 4 are used as inhibitors, butyl xanthate and ethyl xanthate are used as collectors, and when ZnSO 4 and Na 2 S are used respectively, the amount of ZnSO 4 and Na 2 S is 4×10 − When 4 mol/l, the artificial mixed minerals can be completely separated. The copper concentrate can contain 69.55% Cu and 3.44% Ni. The nickel concentrate contains Ni 67.33% and Cu 2.63%. The sum of mutual inclusion is 6.07. The preferred indicator of %. (5) High-ice nickel flotation separation test A sample taken from a non-ferrous smelter, where 29.8% copper, 41.5% nickel, 20.46% sulfur, 3.41% iron-containing, metallic minerals mainly hexagonal nickel sulfur, chalcocite copper and iron-nickel alloy . In order to further determine the optimal dosage of each factor, according to the artificial mixed mineral separation test conditions and the three main factors of the inhibitor Na 2 S and ZnS0 4 dosage and medium pH value, the influence of the selection index, and the test under various factors Based on the selected conditional test. Under the optimal conditions determined by the factors determined by one rough selection, one sweep, and three selected processes, the nickel concentrate was 2.6% copper, the copper concentrate was 3.8% nickel, copper nickel concentrate. The best combination of 6.4% of the minerals in the mine, the sorting effect is obvious. (VI) Mechanism of inhibition of Na 2 S on Ni 3 S 2 flotation The inhibitory effect of Na 2 S on sulfide minerals is generally considered to be mainly two aspects [1] . One is the hydrolysis of Na 2 S to produce HS - , HS - to remove the xanthate adsorbed on the surface of sulfide minerals, while itself adsorbing on the surface of minerals to increase the hydrophilicity of the mineral surface; on the other hand, it is believed that Na 2 S inhibits not only HS - adsorbed on the surface of minerals, should also be related to S 2- produced by Na 2 S ionization. For example, when Na 2 S and xanthate are added to galena, the following balance exists. PbS]PbS↔Pb 2+ +S 2- ↕ 2X - PbS]PbX 2 Since the solubility product of PbX 2 is large, and the solubility product of PbS is small, when Na 2 S is added, the concentration of S 2 increases, and the equilibrium shifts to the left, so that the xanthate attached to the mineral surface is desorbed to form a fresh surface. On the other hand, S 2- of the mineral surface hinders the adsorption of X − ions, so that Na 2 S has an inhibitory effect on the mineral surface. In order to clarify the inhibition behavior of Na 2 S on Ni 3 S 2 flotation, the amount of xanthate adsorbed on the surface of Ni 3 S 2 flotation was measured in the presence or absence of Na 2 S. The results are shown in Table 2. The results indicated that the presence of Na 2 S hindered the adsorption of xanthate on the surface of Ni 3 S 2 flotation. The main reason may be that S 2- and HS - produced competitive adsorption on the mineral surface. From the distribution map of the sulfur component of the Na 2 S solution [2] (Fig. 5), it can also be seen that when the medium pH is about 11.0, the dominant components are HS - and S 2- . The reason for the activation of Ni 3 S 2 at a certain amount may be that Na 2 S is a reducing agent. The slurry potential can be adjusted, and the slurry potential condition at this time is just favorable for the floating of Ni 3 S 2 . According to research [3] The floatability of Ni 3 S 2 is not only related to the pH value of the medium, but also closely related to the potential. Table 2 Determination of the adsorption amount of mineral surface Na 2 S dosage (mol/l) Adding amount of xanthate (mol/l) Mineral surface xanthate adsorption amount mol Pulp pH 0 4×10 -4 5×10 -6 5×10 -6 3.06×10 -6 4.05×10 -7 11.0 11.0 Third, the conclusion From the single mineral test results and the artificial mixed mineral flotation separation test, it is shown that Na 2 S has a strong inhibitory effect on Ni 3 S 2 under the proper medium pH value, and the effect of mixing with ZnSO 4 is better. Effective separation of Cu 2 S and Ni 3 S 3 in high ice nickel. Inhibition of Na 2 S 3 S Ni 2 may be the main reason for the hydrolysis and ionization HS Na 2 S generated -, S 2- produces a competitive adsorption on its surface, thus preventing adsorption xanthate, from inhibition. references 1. Zhu Yushuang Zhu Jianguang Chemical Principles of Flotation Reagents Changsha Zhongnan University of Technology Press, 1987, P.231 2. Wang Dianzu Hu Yuehua Flotation Solution Chemistry Changsha Hunan Science and Technology Press, 1988, P.20 3. Master's thesis of Zhongnan University of Technology, Qiu Ting Province, 1996, P.53 Originally published in the article "Non-ferrous metals" 1997,11, Vol. 49. No. 4 ☺ Flexible Screw Conveyor,Flexible Cement Auger Conveyor,Flexible Cement Conveyor System,Grain Flexible Screw Conveyor Xinxiang Zhenying Mechanical Equipment Co., Ltd , https://www.beltconveyor.nl