Calcium-magnesium mineral inhibitor and method for direct flotation of copper oxide

Abstract

The invention discloses a calcium-magnesium mineral inhibitor and a method for direct flotation of copper oxide, and belongs to the technical field of ore flotation. The method comprises the following steps: carrying out pulp mixing on raw ore simultaneously containing copper oxide minerals and calcium magnesium gangue minerals to obtain ore pulp; a flotation reagent containing the calcium-magnesium mineral inhibitor and the copper oxide mineral collecting agent in the formula I is added into the ore pulp for flotation, and copper oxide foam concentrate and calcium-magnesium gangue tailings are obtained. The inhibitor has good water solubility, mildness and high selectivity, when the inhibitor is used for direct flotation of copper oxide, calcium magnesium gangue mineral dolomite can be selectively inhibited, the copper oxide mineral cannot be inhibited due to the complexing property of phosphate radicals of the inhibitor, and therefore the floatability difference between copper oxide ore and dolomite is enhanced, and the flotation efficiency of copper oxide ore is improved. The method has high copper recovery rate and selectivity, and meanwhile, the subsequent wet smelting production cost of the copper oxide concentrate is remarkably reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of ore flotation, and in particular relates to a calcium-magnesium mineral inhibitor and a method for positive flotation of copper oxide. Background Art

[0002] Copper metal is widely used in the defense industry, electronics and electrical appliances, and the development of new technologies, which has led to an increasing demand for copper metal. Copper ore is a non-renewable strategic resource. With the exploitation and utilization of copper ore resources, sulfide copper ores and rich ores are decreasing, and difficult-to-select oxidized copper ores have been developed and utilized. However, the exploitation of medium- and high-grade oxidized copper ore resources is becoming increasingly exhausted, and low-grade oxidized copper ores are gradually being utilized. Nowadays, for low-grade oxidized copper ores, a large amount of gangue minerals containing calcium and magnesium carbonates, such as dolomite, are often associated. Direct leaching of such minerals will consume a large amount of acid, greatly increasing production costs. The conventional "sulfide-xanthate" flotation will cause a large amount of dolomite to be entrained in the copper concentrate, seriously affecting the grade of the copper concentrate, and increasing the acid consumption in the back-end hydrometallurgical process, significantly increasing production costs. Therefore, it is of great significance to find a dolomite efficient inhibitor for positive flotation of low-grade high-calcium and magnesium oxidized copper ores to enhance the separation of useful minerals and gangue minerals.

[0003] At present, the most commonly used dolomite inhibitors are mainly water glass, sodium hexametaphosphate, sodium carboxymethyl cellulose (CMC) and sodium tripolyphosphate, but the disadvantages of these inhibitors are poor selectivity, large dosage and high cost. Some researchers have studied new organic inhibitors, such as Chinese patent application CN112371346A reported "a dolomite inhibitor and its application method", which uses iminodisuccinate as a dolomite inhibitor and is successfully applied to the flotation of phosphate ore apatite and magnesium-containing carbonate minerals, but has poor selectivity for oxidized copper ores such as malachite. Chinese patent application CN103691574A reported "a method for preparing a dolomite inhibitor and its application", which prepares dolomite inhibitors by using sulfuric acid, hydrochloric acid, benzoic acid and sulfate in a certain proportion, but the preparation cost is high and it is easy to cause environmental pollution. Chinese patent application CN111215251A reported "a dolomite inhibitor and its use method", which is to prepare a dolomite inhibitor by mixing xanthan gum and pullulan at mass fractions of 80-95% and 5-20% respectively, but the preparation cost is relatively high. Chinese patent application CN117943209A announced "a combined inhibitor and its application in the flotation of fine-grained copper oxide ore", which combines aminotriacetic acid, lactic acid, tannin extract and polyferric sulfate to prepare an inhibitor to separate fine-grained copper oxide ore from gangue minerals, but the preparation process is cumbersome and the cost is relatively high. Chinese patent application CN109261346A reported "a beneficiation method for copper-cobalt ore containing easily floatable calcium-magnesium minerals", which is to add at least one of carboxymethyl cellulose, carboxyethyl cellulose and guar gum to inhibit calcium-magnesium minerals, and the cost of the reagent is relatively high, which is not conducive to large-scale promotion and application. Chinese patent application CN108654844A discloses an organophosphate compound used as a flotation inhibitor for calcium-containing gangue minerals, and used for flotation separation of scheelite and calcium-containing gangue minerals. The method is to esterify and hydrolyze phosphorus trichloride, R-COOH and water to obtain the organophosphate compound. However, the preparation process is complicated, the water solubility is poor, and the organophosphate compound contains two phosphoric acid groups with strong complexing ability, resulting in poor selectivity for similar carbonate minerals, and cannot be applied to the flotation system of low-grade copper oxide ores. Summary of the invention

[0004] In order to solve the problems existing in the prior art such as poor water solubility of calcium and magnesium mineral inhibitors and poor selectivity for similar carbonate minerals, the first object of the present invention is to provide a calcium and magnesium mineral inhibitor, which has good water solubility and mildness as well as high selectivity and has excellent universality with the copper oxide ore flotation system.

[0005] The second object of the present invention is to provide a method for the positive flotation of copper oxide using a calcium-magnesium mineral inhibitor, which can selectively inhibit the calcium-magnesium gangue mineral dolomite by adding a small amount of the calcium-magnesium mineral inhibitor, without inhibiting the copper oxide mineral due to the complexing property of its phosphate group, thereby enhancing the floatability difference between the copper oxide ore and the dolomite, and having a higher copper recovery rate and selectivity.

[0006] In order to achieve the above technical objectives, the present invention provides a calcium magnesium mineral inhibitor having the following structural formula:

[0007] ;

[0008] Formula I;

[0009] Wherein, M represents a metal ion.

[0010] The inhibitor of the present invention has suitable complexing ability and good water solubility for calcium and magnesium minerals, which is the key to ensure good inhibitory effect and high selectivity on calcium and magnesium minerals. Specifically, at present, glycerophosphates include α-glycerophosphate and β-glycerophosphate. The inhibitor of the present invention belongs to α-glycerophosphate. This is because the phosphate group of the present invention is at the terminal position compared with β-glycerophosphate. In the process of flotation of calcium and magnesium, it can cooperate with the multiple hydroxyl complexes to form a more compact and stable five-membered ring or six-membered ring structure adsorption layer, which effectively inhibits the adsorption of the collector; at the same time, the dibasic phosphate group has a strong complexing property compared with the monobasic phosphate group of the present invention, and for similar carbonate minerals (such as malachite CuCO 3 •Cu(OH) 2 、Dolomite CaMg(CO 3 ) 2 ) have complexing effects, which makes it difficult to distinguish the target metals in different minerals, resulting in poor selectivity. At the same time, the monobasic phosphoric acid group in the present invention is not directly connected to the hydrocarbon group, and there is steric hindrance between the monobasic phosphoric acid group and the hydroxyl group, which also improves the hydrophilicity and selectivity of the inhibitor of the present invention to a certain extent.

[0011] Furthermore, the inhibitor of the present invention can be used for the positive flotation of copper oxide ore to remove dolomite, a calcium-magnesium gangue mineral, wherein the copper oxide ore includes artificial mixed ore and actual industrial copper oxide mineral flotation.

[0012] As a preferred solution, M in the present invention may be sodium, and the glycerophosphate in the present invention also includes its hydrate.

[0013] The present invention also provides a method for using a calcium magnesium mineral inhibitor for positive flotation of copper oxide. The method comprises the steps of preparing a pulp of an ore containing both copper oxide minerals and calcium magnesium gangue minerals; and adding a calcium magnesium mineral inhibitor containing the formula The flotation is carried out using flotation reagents including calcium and magnesium mineral inhibitors and copper oxide mineral collectors to obtain copper oxide foam concentrate and calcium and magnesium gangue tailings.

[0014] The calcium-magnesium mineral inhibitor of the present invention has a strong selective inhibitory effect on the calcium-magnesium carbonate mineral dolomite in the oxidized copper ore. By adding the inhibitor, the useful mineral malachite and the gangue mineral dolomite in the positive flotation of the oxidized copper ore can be efficiently separated. The main mechanism is:

[0015] The inhibitor contains a large number of hydroxyl groups and suitable phosphate groups and other hydrophilic and solid groups. Although malachite and dolomite are both carbonate minerals, due to the difference in crystal structure between malachite and dolomite ores and the good water solubility of the inhibitor, it can spatially match the Ca and Mg active sites exposed on the surface of dolomite, strongly adsorb on the surface of dolomite through the coordination reaction mechanism, and produce a hydrophilic film to make the surface of dolomite hydrophilic, thereby achieving selective inhibition of gangue minerals in oxidized copper ore, further preventing the adsorption of collectors, and increasing the floatability difference between oxidized copper minerals and gangue minerals. Malachite has a small surface copper ion radius and a large charge density, and its coordination with the inhibitor is inhibited by the steric hindrance effect. Through the synergistic effect of the collector, it can be more easily adsorbed on its surface, thereby achieving efficient separation of oxidized copper minerals and calcium-magnesium gangue minerals.

[0016] As a preferred solution, the pH range of the slurry is 6 to 12. Within the pH range of the present invention, a high recovery rate of copper in copper oxide minerals and a high selective inhibition of calcium and magnesium can be effectively achieved. It is further preferred that the pH range of the slurry is 9 to 12.

[0017] As a preferred solution, the dosage of the calcium-magnesium mineral inhibitor is 10-100 mg / L. As the concentration of the inhibitor increases, the flotation of malachite is almost unaffected, while the recovery rate of dolomite is significantly reduced. It is further preferred that the dosage of the inhibitor is 60-100 mg / L.

[0018] As a preferred solution, the flotation reagent also includes a sulfiding agent in an amount of 100-500 mg / L and a frother in an amount of 35-50 mg / L. The sulfiding agent used in the present invention is further preferably sodium sulfide and / or sodium hydrosulfide. In the flotation process of copper oxide minerals, the present invention can change the surface chemical properties of copper oxide minerals through surface sulfidation reaction by adding a sulfiding agent, so that it is converted into a hydrophobic surface of sulfide ore, thereby improving the adsorption capacity of xanthate collectors. Adding a frother can further increase the floatability of the mineral.

[0019] As a preferred solution, the collector includes xanthate collectors and / or fatty acid collectors, and the dosage is 80 - 500 mg / L. Further, the xanthate collectors used in the present invention include butyl xanthate and / or amyl xanthate, and the fatty acid collectors used include sodium oleate.

[0020] As a preferred solution, the raw ore includes malachite and dolomite.

[0021] As a preferred solution, the copper grade in the raw ore is greater than or equal to 0.5%, the calcium grade is greater than or equal to 5%, and the magnesium grade is greater than or equal to 5%. The direct flotation method of the present invention also has good effects on the recovery of copper in low-grade high-calcium and high-magnesium copper oxide ores.

[0022] Compared with the prior art, the present invention has the following beneficial technical effects:

[0023] (1) The inhibitor provided by the present invention has good water solubility, mildness and high selectivity, and has excellent universality with the copper oxide ore flotation system.

[0024] (2) The inhibitor provided by the present invention has a small dosage, low cost, safe use, wide source, non-toxic, strong biodegradability, and can effectively achieve high recovery of copper in copper oxide minerals and high selective inhibition of calcium and magnesium within a relatively wide pH range.

[0025] (3) The inhibitor provided by the present invention has a strong selective inhibitory effect on calcium and magnesium carbonate minerals in copper oxide ores. By adding the inhibitor, efficient separation of the useful mineral malachite and the gangue mineral dolomite in the direct flotation of copper oxide ores can be achieved.

[0026] (4) The inhibitor provided by the present invention has good separation effects in both artificial mixed ores and actual industrial copper oxide ores, and has good industrial popularization and application value.

[0027] (5) The flotation separation method of the present invention has a simple process. By adding a small amount of α-glycerophosphate inhibitor, the calcium and magnesium gangue mineral dolomite can be selectively inhibited without inhibiting copper oxide minerals due to the complexing property of its phosphate group, thereby enhancing the floatability difference between copper oxide ores and dolomite, having high copper recovery and selectivity, and significantly reducing the wet smelting production cost of subsequent copper oxide concentrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is the direct flotation reagent regime and flow chart of the artificial mixed ore and the actual copper oxide ore of the present invention.

[0029] Figure 2 It is the experimental result of Example 1 of the present invention.

[0030] Figure 3 This is the infrared spectrum of dolomite before and after the action of the α-glycerophosphate inhibitor of the present invention.

[0031] Figure 4 These are the experimental results of Example 2 of the present invention.

[0032] Figure 5 The experimental results of comparative example 1 of the present invention are shown in FIG. DETAILED DESCRIPTION

[0033] The following specific examples are intended to further illustrate the content of the present invention, but are not intended to limit the scope of protection of the claims of the present invention. The pharmaceutical agents used without indicating the manufacturer are all conventional products that can be purchased commercially.

[0034] The slurry concentration in the present invention refers to the mass concentration, and the amount of reagents used is the amount relative to the original ore.

[0035] Example 1

[0036] The pure malachite and dolomite minerals with a particle size of -0.074~+0.037 mm were uniformly mixed in a mass ratio of 1:9, 2 g of the artificial mixed ore was taken, 35 mL of deionized water was added to the flotation tank, and the slurry was stirred at a speed of 1560 r / min. The order and process of adding the flotation reagents are as follows: Figure 1 As shown, the pH of the slurry was adjusted to 8, and 10, 20, 40, 60, 80, and 100 mg / L of the inhibitor α-glycerophosphate disodium were added in sequence; the collector was sodium oleate 80 mg / L; then flotation was performed for 5 minutes to obtain the foam product and tailings, which were then filtered, dried, and weighed, and the recovery rate was calculated. The results are shown in Figure 2 The infrared spectra of dolomite before and after the inhibitor is applied are shown in Figure 3 As shown. Among them, the structural formula of α-glycerophosphate disodium is as follows:

[0037] ;

[0038] Formula I;

[0039] Wherein, M is sodium.

[0040] As can be seen from Example 1, as the inhibitor concentration increases, the flotation of malachite is almost unaffected, while the recovery rate of dolomite is significantly reduced. When the inhibitor concentration is 60 mg / L, the recovery rate of malachite is 90.13%, while the recovery rate of dolomite is only 14.27%. Figure 3 It can be seen that after the inhibitor α-glycerophosphate disodium was used, a new characteristic peak of 3427.51 cm appeared on the surface of dolomite. -1 and 1433.11cm -1They correspond to -OH and -P=O groups, respectively, indicating that the inhibitor can be adsorbed on the surface of dolomite and has a selective inhibitory effect on dolomite.

[0041] Example 2

[0042] The pure malachite and dolomite minerals with a particle size of -0.074~+0.037 mm were uniformly mixed in a mass ratio of 1:4, 2 g of the artificial mixed ore was taken, 35 mL of deionized water was added to the flotation tank, and the slurry was stirred at a speed of 1560 r / min. The order and process of adding the flotation reagents are as follows: Figure 1 As shown, the pH of the slurry was adjusted to 6, 7, 8, 9, 10, 11, and 12, and 60 mg / L of inhibitor (α-glycerophosphate disodium) was added in sequence; the collector was 80 mg / L of sodium oleate; then flotation was performed for 5 minutes to obtain foam products and tailings, which were then filtered, dried, and weighed, and the recovery rate was calculated. The results are as follows Figure 4 shown.

[0043] It can be seen from the examples that with the increase of pulp pH, the flotation recovery rate of malachite is basically around 90%, while the recovery rate of dolomite is only around 13%, indicating that the inhibitor has a selective inhibitory effect on dolomite in a wide pH range.

[0044] Comparative Example 1

[0045] The pure malachite and dolomite minerals with a particle size of -0.074~+0.037 mm were uniformly mixed in a mass ratio of 1:9, 2 g of the artificial mixed ore was taken, 35 mL of deionized water was added to the flotation tank, and the slurry was stirred at a speed of 1560 r / min. The order and process of adding the flotation reagents are as follows: Figure 1 As shown, the pH of the slurry was adjusted to 8, and the inhibitor disclosed in patent CN108654844A (chemical formula: C 2 H 8 O 7 P 2 ), add 20, 40, 60, 80, 100 mg / L of inhibitor in turn; the collector is 80 mg / L of sodium oleate; then float for 5 minutes to obtain foam products and tailings, and then filter, dry, weigh, and calculate the recovery rate. The results are as follows Figure 5 As shown. It can be seen that the recovery rates of malachite and dolomite are both reduced, indicating that the inhibitor has poor selectivity and it is difficult to achieve effective separation of malachite and dolomite. Among them, the inhibitor structure is as follows:

[0046]

[0047] Formula II.

[0048] Example 3

[0049] Take 500 g of actual copper oxide ore from Tibet for crushing and grinding, the grinding concentration is 60%, and the -200 mesh accounts for 70%, and then transfer it to a 1.5 L single-tank flotation machine, the pulp concentration is 30wt%, and the slurry is stirred at a speed of 1920 r / min. The order and process of adding flotation agents are as follows Figure 1 As shown, the pH of the slurry was adjusted to 8.5, and sulfiding agents (Na 2 S, 500 mg / L); inhibitor (α-glycerophosphate disodium) 0, 60 mg / L, collector is amyl xanthate 500 mg / L; frother is No. 2 oil 35 mg / L, then flotation for 5 minutes to obtain foam product and tailings, then filter, dry, weigh, test, calculate the recovery rate, the results are shown in Table 1.

[0050] As shown in Table 1, without adding inhibitors, the Cu grade in the concentrate is 2.55%, the Ca grade is 7.86%, and the Mg grade is 7.07%; the copper recovery rate is 74.19%, the calcium recovery rate is 33.23%, and the magnesium recovery rate is 33.99%, indicating that useful copper minerals and gangue mineral dolomite cannot be effectively separated by positive flotation. After adding 60 mg / L of inhibitors and flotation, the Cu grade in the concentrate is 3.24%, the Ca grade is 1.58%, and the Mg grade is 2.03%; the copper recovery rate is 80.71%, the calcium recovery rate is 5.72%, and the magnesium recovery rate is 8.36%, indicating that the inhibitor of the present invention still has excellent selective inhibition when separating useful minerals from gangue mineral dolomite by positive flotation of actual copper oxide ore.

[0051]

[0052] Comparative Example 2

[0053] Take 500 g of actual copper oxide ore from Tibet for crushing and grinding, the grinding concentration is 60%, and the -200 mesh accounts for 70%, and then transfer it to a 1.5 L single-tank flotation machine, the pulp concentration is 30wt%, and the slurry is stirred at a speed of 1920 r / min. The order and process of adding flotation agents are as follows Figure 1 As shown, the pH of the slurry was adjusted to 8.5, and sulfiding agents (Na 2 S, 500 mg / L); in comparative example 1, the inhibitor dosage is 60 mg / L, the collector is 500 mg / L of amyl xanthate; the foaming agent is 35 mg / L of No. 2 oil, and then flotation is performed for 5 minutes to obtain foam products and tailings, which are then filtered, dried, weighed, and tested, and the recovery rate is calculated. The results are shown in Table 2. As can be seen from Table 2, compared with the inhibitor of the present invention, the chemical formula C 2 H 8 O 7 P 2The copper recovery rate of the inhibitor concentrate was significantly reduced, and the selectivity was also significantly reduced, indicating that the chemical formula was C 2 H 8 O 7 P 2 The inhibitor selectivity is poor and is not suitable for the flotation system of copper oxide ore.

[0054]

[0055] Example 4

[0056] 500 g of actual copper oxide ore from the Democratic Republic of the Congo was weighed and crushed to a grinding concentration of 60%, with -200 mesh accounting for 70%, and then transferred to a 1.5 L single-tank flotation machine with a pulp concentration of 30 wt%, and stirred at a speed of 1920 r / min. The order and process of adding flotation agents are as follows: Figure 1 As shown, the pH of the slurry was adjusted to 8.5, and sulfiding agents (Na 2 S, 500 mg / L); the dosage of inhibitor α-glycerophosphate disodium was 0 and 60 mg / L, the collector was amyl xanthate 500 mg / L; the frother was No. 2 oil 35 mg / L, and then flotation was performed for 5 minutes to obtain foam products and tailings, which were then filtered, dried, weighed, and tested, and the recovery rate was calculated. The results are shown in Table 3.

[0057] As shown in Table 3, without adding inhibitors, the Cu grade in the concentrate is 3.65%, the Ca grade is 10.03%, and the Mg grade is 8.37%; the copper recovery rate is 82.63%, the calcium recovery rate is 39.47%, and the magnesium recovery rate is 38.57%, indicating that useful copper minerals and gangue mineral dolomite cannot be effectively separated by positive flotation. After adding 60 mg / L of inhibitors and flotation, the Cu grade in the concentrate is 4.76%, the Ca grade is 2.56%, and the Mg grade is 2.04%; the copper recovery rate is 83.50%, which has not decreased, while the calcium recovery rate is 7.85%, and the magnesium recovery rate is 7.33%, indicating that the inhibitor of the present invention still has a good selective inhibitory effect when the useful minerals and gangue mineral dolomite are separated by positive flotation in the actual copper oxide ore.

[0058]

Claims

1. A calcium and magnesium mineral inhibitor, characterized in that: It has the following structural formula: ； Formula I; Wherein, M represents a metal ion.

2. The method for using a calcium and magnesium mineral inhibitor for positive flotation of copper oxide according to claim 1, characterized in that: The raw ore containing both copper oxide minerals and calcium magnesium gangue minerals is slurried to obtain slurry; the slurry is added with the formula The flotation is carried out using flotation reagents including calcium and magnesium mineral inhibitors and copper oxide mineral collectors to obtain copper oxide foam concentrate and calcium and magnesium gangue tailings.

3. The method for using a calcium and magnesium mineral inhibitor for positive flotation of copper oxide according to claim 2, characterized in that: The pH range of the slurry is 6-12.

4. The method for using a calcium and magnesium mineral inhibitor for positive flotation of copper oxide according to claim 2 or 3, characterized in that: The dosage of the calcium and magnesium mineral inhibitor is 10-100 mg / L.

5. The method for using a calcium and magnesium mineral inhibitor for positive flotation of copper oxide according to claim 2, characterized in that: The flotation reagent also includes a sulfiding agent in an amount of 100-500 mg / L and a frother in an amount of 35-50 mg / L.

6. The method for using a calcium and magnesium mineral inhibitor for positive flotation of copper oxide according to claim 5, characterized in that: The collector includes a xanthate collector and / or a fatty acid collector, and the dosage is 80-500 mg / L.

7. The method for using a calcium and magnesium mineral inhibitor for positive flotation of copper oxide according to claim 6, characterized in that: The raw ore includes malachite and dolomite.

8. The method for using a calcium and magnesium mineral inhibitor for positive flotation of copper oxide according to claim 7, characterized in that: The copper grade of the raw ore is greater than or equal to 0.5%, the calcium grade is greater than or equal to 5%, and the magnesium grade is greater than or equal to 5%.

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