A method for recovering copper, gold and iron from high-silicon, high-mud copper-gold oxide ore

Abstract

The application discloses a method for recovering copper, gold and iron from high-silicon and high-mud copper oxide gold ore, and belongs to the field of mineral processing engineering. The method comprises the following steps: selecting a part of gold with good floatability in a desliming pretreatment process, reducing the influence on subsequent separation, separating copper oxide minerals by using a flotation method, adjusting flotation reagents and process conditions according to the ore properties, so as to achieve efficient recovery of copper and gold. Iron minerals are recovered by using magnetic separation, economic benefits are increased, the grade of gold in tailings is improved, and the influence of iron minerals on subsequent gravity separation is avoided. Finally, gravity separation is used to recover gold in the tailings, so that the maximum recovery of gold resources is ensured. The application combines multiple beneficiation processes, optimizes the mineral separation process, improves the metal recovery rate and reduces resource waste. The method has the advantages that the recovery rates of copper, gold and iron are greatly improved through the optimized beneficiation process, and the loss of useful metals in the ore is minimized.

Description

Technical Field

[0001] The invention belongs to the technical field of mineral processing engineering, and in particular relates to a beneficiation method for recovering copper, gold and iron from high-silicon, high-mud oxide copper-gold ore. Background Art

[0002] High-mud copper-oxide gold ore refers to gold ore containing high levels of clay minerals (mud) and copper oxide. This type of ore has a complex mineral composition, containing gold, copper, silver, iron, and other elements. Copper primarily exists as an oxide (such as malachite and azurite), while gold typically exists as either pure gold or supported gold. It also contains copper oxides (such as malachite and azurite) and argillaceous minerals (such as kaolin and montmorillonite).

[0003] The presence of high-mud minerals has a negative impact on traditional gold and copper ore processing processes. Mud minerals have fine particles and strong colloidal properties on their surface, which easily adsorb metal ions, thereby reducing metal recovery rates. In addition, mud minerals may hinder the penetration of the solution during solvent leaching, reducing the leaching effect. The gold in high-mud copper-gold oxide ores usually exists in the form of tiny particles and may be closely associated with copper minerals. In this case, gold recovery is often interfered with by other minerals (such as copper, iron, mud minerals, etc.), making the recovery process complicated and the recovery rate low.

[0004] The first step in processing high-mud copper-gold oxidized ores is to remove the mud minerals. Common methods include physical desludging and flotation desludging. These methods help separate the mud minerals and reduce their impact on subsequent processing, but the desludging process also causes some metal loss. For copper and gold, flotation, leaching, gravity separation, or combined treatment processes are commonly used, but each has various shortcomings. Summary of the Invention

[0005] The present invention aims to provide a beneficiation method for recovering copper, gold, and iron from copper-gold oxide ores with high mud content, silicate content, and oxidation rate. Addressing the shortcomings of current copper-gold oxide ores, and taking into account the inherent characteristics of high mud, high silica, and high oxidation rate, a combined process of grinding followed by gold-slime separation, copper-gold separation, magnetic iron separation, and gravity gold separation is employed to ultimately produce gold, copper, and iron concentrates.

[0006] The specific steps are as follows:

[0007] (1) Grinding: The grinding concentration of the raw ore is 55-65%. 500-1000g / t of Na2CO3 and 500-1500g / t of ammonium sulfate are added during grinding. The grinding fineness is less than 0.074mm and the content is 70-80%. The ore pulp has a mass percentage concentration of 28-35%.

[0008] (2) Gold mud flotation: 5-15 g / t of 2# oil, 10-20 g / t of Z-200 and 5-15 g / t of butyl ammonium black powder are added to the slurry obtained in step (2), and after 1-2 roughing, 1-2 cleaning and 1-2 scavenging, gold concentrate I and tailings slurry I with a mass percentage concentration of 25-32% are obtained. The gold concentrate I obtained has a gold grade of 35-50 g / t and a recovery rate of 25-30%.

[0009] (3) Copper oxide flotation: dispersant, sulfiding agent, ammonium sulfate, collector, and frother are sequentially added to the tailings slurry I obtained in step (2), and copper concentrate and tailings slurry II are obtained after 1-2 roughing, 1-3 cleaning, and 1-2 scavenging. The copper concentrate has a copper grade of 15-18%, a copper recovery rate of 50-60%, a gold content of 30-45 g / t, and a gold recovery rate of 35-40%.

[0010] (4) Magnetic iron separation: The tailings slurry II obtained in step (3) is fed into a magnetic separator, and subjected to 1-2 roughing separations and 1-2 cleaning separations to obtain iron concentrate and tailings slurry III. The obtained iron concentrate has an iron grade of 55-62%;

[0011] (5) Gold reselection: The tailings slurry III obtained in step (4) is graded and re-grinded and then fed into the reselection process to obtain gold concentrate II and final tailings. The gold grade of gold concentrate II is 35-50g / t, and the gold recovery rate is 5-10%.

[0012] The raw ore of copper-gold oxide has a copper grade of 0.7-1.2%, a gold grade of 1.5-3.0 g / t raw ore, a copper oxidation rate of 50-90%, a primary mud content of 15-40%, and gangue minerals such as chlorite, talc, tremolite, and mica.

[0013] In step (3) copper oxide flotation, the dispersant composition and mass ratio are propylene glycol: sodium hexametaphosphate: CMC = 3 parts: 4 parts: 3 parts; the vulcanizing agent is: one or more of sodium sulfide, sodium hydrosulfide, and Na2S4; the collecting agent is: one or a mixture of any ratio of amyl xanthate, isoamyl xanthate, and butyl ammonium black medicine; and the foaming agent is: one or more of 2# oil, MIBC, kerosene, and diesel.

[0014] In step (3), the amounts of dispersant, vulcanizing agent, ammonium sulfate, collector and foaming agent are 600-1000 g / t, 1-3 kg / t, 1-3 kg / t, 200-500 g / t and 5-30 g / t respectively.

[0015] The reselection operation in step (5) is one or more of shaking table, spiral chute, and Nelson. If a spiral chute + shaking table is used, the tailings slurry is first fed into the spiral chute after being graded and re-grinded at level III, and the resulting concentrate is then fed into the shaking table to improve the gold grade of the gold concentrate; if a Nelson + shaking table is used, the tailings slurry is first fed into the Nelson after being graded and re-grinded at level III, and the resulting concentrate is then fed into the shaking table to improve the gold grade of the gold concentrate.

[0016] Compared with the existing recovery method of copper oxide gold ore, the present invention has the following advantages:

[0017] (1) The present invention adopts a flotation-magnetic separation-gravity separation combined process to maximize the recovery and utilization of copper, gold and iron minerals.

[0018] (2) The present invention addresses the characteristics of high-silicon, high-mud copper-gold oxide ores. First, during the desludging process, a portion of the gold with good floatability is selected, thereby achieving the principle of early collection when possible, and reducing the impact of the ore mud on subsequent copper-gold selection operations. Furthermore, compared to conventional copper oxide desludging flotation, the present invention avoids the loss of precious metal gold during the desludging process.

[0019] (3) The present invention selects copper oxide to enhance the capture of gold carriers, allowing gold to be enriched in copper concentrate, thereby achieving comprehensive recovery of copper and gold.

[0020] (4) The present invention performs magnetic separation on flotation tailings to separate iron, (1) ensuring the recovery of iron minerals such as magnetite and hematite, thereby increasing the efficiency; (2) after a portion of the iron minerals are separated, the gold in the tailings is further enriched, the gold grade is improved, and the cost of subsequent processing is reduced; (3) conditions are created for further recovery of gold by graded regrinding and gravity separation. The particle size and specific gravity of the minerals have a greater impact on gravity separation. Prioritizing the separation of iron minerals not only reduces the processing volume of regrinding, but also improves the efficiency of gravity separation.

[0021] (5) The present invention classifies and regrinds the tailings after iron selection to dissociate a portion of the gold wrapped in the conjoined bodies and gangue, and then recovers the gold through gravity separation, thereby realizing the maximum recovery of gold.

[0022] (6) The present invention makes full use of the difference in gold selectivity and recovers precious metal gold in the three operations of desludging, copper selection and gravity selection, thereby achieving maximum utilization of gold.

[0023] (7) The present invention reduces the emission of pollutants commonly found in traditional mineral processing methods and meets environmental protection requirements. The present invention adopts efficient equipment and processes, reduces energy consumption, and lowers production costs. This mineral processing method provides a feasible technical route for the comprehensive recovery of high-silicon, high-mud, and high-oxidation-rate copper-gold oxide ores, and has good application prospects and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a process flow chart of Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The following is a further description of the ore dressing method for recovering copper, gold and iron from high-silicon, high-mud copper-gold ore according to the present invention with reference to specific embodiments.

[0026] Example 1:

[0027] (1) Ore: A copper-gold oxide mine in Xinjiang. The copper grade in the mine is between 0.70-1.0%, the copper oxidation rate is 50-75%, the gold grade is 1.5-2.5g / t, the mud content is 15-25%, and the iron minerals are magnetite and hematite. The ore is mostly beige or gray, with a few being reddish brown. The gangue minerals are mainly silicate minerals such as chlorite, talc, and tremolite. Figure 1 Schematic diagram of the process flow of this embodiment.

[0028] (2) Grinding: The ore grinding concentration is 55%, and 500 g / t of Na2CO3 and 500 g / t of ammonium sulfate are added to the ore. The grinding fineness is less than 0.074 mm and the content is 70%, obtaining a slurry with a mass percentage concentration of 28%;

[0029] (3) Gold mud flotation: 5 g / t of 2# oil, 10 g / t of Z-200 and 10 g / t of butyl ammonium black powder were added to the pulp with a mass percentage concentration of 28% obtained in step (2), and after one roughing, one cleaning and one scavenging, gold concentrate I and tailings pulp I with a mass percentage concentration of 25% were obtained; the gold grade of the obtained gold concentrate I was 35.6 g / t, and the gold recovery rate was 28.5%;

[0030] (4) Copper oxide flotation: dispersant, sulfiding agent, ammonium sulfate, collector and foaming agent are sequentially added to the tailings pulp I obtained in step (3), with the dosage of 600 g / t, 1 kg / t, 1 kg / t, 300 g / t and 10 g / t respectively. After 2 roughing, 2 cleaning and 2 scavenging, copper concentrate and tailings pulp II are obtained. The copper concentrate has a copper grade of 15.6%, a copper recovery rate of 52.5%, a gold content of 33.5 g / t and a gold recovery rate of 36.5%. The dispersant composition is propylene glycol: sodium hexametaphosphate: CMC = 3 parts: 4 parts: 3 parts; the sulfiding agent is: sodium sulfide: Na2S4 in a ratio of 1:1; the collector is: amyl xanthate: isoamyl xanthate: butyl ammonium black medicine in a ratio of 1:1:1; and the foaming agent is MIBC.

[0031] (5) feeding the tailings slurry II obtained in step (4) into a magnetic separator, and subjecting it to one roughing separation and one cleaning separation to obtain iron concentrate and tailings slurry III; the iron grade of the obtained iron concentrate is 56.5%, and the iron recovery rate is 25.6%;

[0032] (6) The tailings slurry III obtained in step (5) is graded and re-grinded and then fed into a gravity separation process to obtain gold concentrate II and final tailings. The gravity separation equipment used is a spiral chute plus a shaking table. After the tailings slurry III is graded and re-grinded, it is first fed into the spiral chute, and the resulting concentrate is then fed into the shaking table to improve the gold grade in the gold concentrate. The gold grade of the resulting gold concentrate II is 42g / t, and the gold recovery rate is 6.0%;

[0033] (7) The final copper recovery rate was 52.5%, the total gold recovery rate was 72%, and the iron recovery rate was 25.6%.

[0034] Example 2

[0035] (1) Ore: This ore is from a copper-gold oxide mine in Kyrgyzstan. The copper grade is 0.70-1.1%, the copper oxidation rate is 70-90%, the gold grade is 1.8-2.8g / t, the mud content is 20-30%, and the iron minerals are magnetite and limonite. The ore is mostly brownish yellow, yellow-green, or brown. The gangue minerals are mainly diopside, calcite, talc, serpentine, etc.

[0036] (2) Grinding: The ore is ground to a concentration of 60%, and 800 g / t of Na2CO3 and 1000 g / t of ammonium sulfate are added to the ore. The grinding fineness is less than 0.074 mm and the content is 75%, obtaining a slurry with a mass percentage concentration of 30%;

[0037] (3) Gold mud flotation: 10 g / t of 2# oil, 15 g / t of Z-200 and 5 g / t of butyl ammonium black powder were added to the pulp with a mass percentage concentration of 30% obtained in step (2), and after one roughing, two cleaning and one scavenging, gold concentrate I and tailings pulp I with a mass percentage concentration of 27% were obtained; the gold grade of the obtained gold concentrate I was 40.5 g / t, and the gold recovery rate was 27.5%;

[0038] (4) Copper oxide flotation: dispersant, sulfiding agent, ammonium sulfate, collector and foaming agent are sequentially added to the tailings pulp I obtained in step (3), with the dosage of 800 g / t, 2 kg / t, 2 kg / t, 200 g / t and 5 g / t respectively. After 2 roughing, 2 cleaning and 1 scavenging, copper concentrate and tailings pulp II are obtained. The copper concentrate has a copper grade of 16.8%, a copper recovery rate of 55.4%, a gold content of 38.5 g / t and a gold recovery rate of 38.5%. The dispersant composition is propylene glycol: sodium hexametaphosphate: CMC = 3 parts: 4 parts: 3 parts; the sulfiding agent is sodium hydrosulfide: Na2S4 in a ratio of 1:1; the collector is amyl xanthate: isoamyl xanthate: butyl ammonium black medicine in a ratio of 1:1:1; the foaming agent is MIBC: kerosene in a ratio of 1:1;

[0039] (5) feeding the tailings slurry II obtained in step (4) into a magnetic separator, and subjecting it to two roughing separations and one fine separation to obtain iron concentrate and tailings slurry III; the iron grade of the obtained iron concentrate is 55.5%, and the iron recovery rate is 28.5%;

[0040] (6) The tailings slurry III obtained in step (5) is graded and re-ground, and then fed to a gravity separation operation to obtain gold concentrate II and final tailings. The gravity separation equipment used is a Nelson plus shaking table. After the tailings slurry III is graded and re-ground, it is first fed to the Nelson, and the resulting concentrate is then fed to the shaking table to improve the gold grade of the gold concentrate. The gold grade of the resulting gold concentrate 2 is 35.5g / t, and the gold recovery rate is 8.0%.

[0041] (7) The final copper recovery rate was 55.4%, the total gold recovery rate was 74%, and the iron recovery rate was 28.5%.

[0042] Example 3

[0043] (1) Ore: This ore is from a copper-gold oxide mine in the Democratic Republic of the Congo. The copper grade is 0.80-1.20%, the copper oxidation rate is 50-70%, the gold grade is 2.2-3.0 g / t, the mud content is 25-40%, and the iron minerals are hematite and magnetite. The ore structure mainly includes massive structure, disseminated structure and banded structure. The gangue minerals are mainly diopside, andradite, calcite, talc, quartz, etc.

[0044] (2) Grinding: The ore is ground to a concentration of 65%, and 1000 g / t of Na2CO3 and 1500 g / t of ammonium sulfate are added to the ore. The grinding fineness is less than 0.074 mm and the content is 80%, obtaining a slurry with a mass percentage concentration of 35%;

[0045] (3) Gold mud flotation: 15 g / t of 2# oil, 20 g / t of Z-200 and 15 g / t of butyl ammonium black powder were added to the pulp with a mass percentage concentration of 35% obtained in step (2), and after one roughing, two cleaning and two scavenging, gold concentrate I and tailings pulp I with a mass percentage concentration of 32% were obtained; the gold grade of the obtained gold concentrate I was 45.5 g / t, and the gold recovery rate was 30.0%;

[0046] (4) dispersant, sulfiding agent, ammonium sulfate, collector, foaming agent, etc. are sequentially added to the tailings slurry I obtained in step (3), and the dosages thereof are 1000 g / t, 3 kg / t, 3 kg / t, 500 g / t, and 30 g / t, respectively. After 2 roughing, 3 cleaning, and 2 scavenging, copper concentrate and tailings slurry II are obtained. The copper concentrate has a copper grade of 17.2%, a copper recovery rate of 57.2%, a gold content of 41.5 g / t, and a gold recovery rate of 36.0%. The dispersant composition is propylene glycol: sodium hexametaphosphate: CMC = 3 parts: 4 parts: 3 parts; the sulfiding agent is sodium sulfide: sodium hydrosulfide: Na2S4 in a ratio of 1:1:1; the collector is amyl xanthate: butyl xanthate: butylammonium black medicine in a ratio of 1:1:1; and the foaming agent is MIBC: kerosene in a ratio of 1:1;

[0047] (5) feeding the tailings slurry II obtained in step (4) into a magnetic separator, and subjecting it to one roughing separation and two cleaning separations to obtain iron concentrate and tailings slurry III; the iron grade of the obtained iron concentrate is 62.0%, and the iron recovery rate is 27.6%;

[0048] (6) The tailings slurry III obtained in step (5) is graded and re-grinded and then fed into a gravity separation process to obtain gold concentrate II and final tailings. The gravity separation equipment used is Nelson. The gold grade of the obtained gold concentrate II is 45.5g / t, and the gold recovery rate is 10.0%.

[0049] (7) The final copper recovery rate was 57.2%, the total gold recovery rate was 76%, and the iron recovery rate was 27.6%.

Claims

1. A method for recovering copper, gold and iron from high-silicon, high-mud copper-gold ore, characterized in that: The specific steps are as follows: (1) Grinding: The grinding concentration of the raw ore is 55-65%. 500-1000g / t of Na2CO3 and 500-1500g / t of ammonium sulfate are added during grinding. The grinding fineness is less than 0.074mm and the content is 70-80%. The ore pulp has a mass percentage concentration of 28-35%. (2) Gold mud flotation: 5-15 g / t of 2# oil, 10-20 g / t of Z-200, and 5-15 g / t of butyl ammonium black powder are added to the slurry obtained in step (2), and after 1-2 roughing, 1-2 cleaning, and 1-2 scavenging, gold concentrate I and tailings slurry I with a mass percentage concentration of 25-32% are obtained; (3) Copper oxide flotation: dispersant, sulfiding agent, ammonium sulfate, collector, and frother are sequentially added to the tailings slurry I obtained in step (2), and copper concentrate and tailings slurry II are obtained after 1-2 roughing, 1-3 cleaning, and 1-2 scavenging. (4) Magnetic iron separation: feeding the tailings slurry II obtained in step (3) into a magnetic separator, and undergoing 1-2 roughing separations and 1-2 cleaning separations to obtain iron concentrate and tailings slurry III; (5) Gold reselection: The tailings slurry III obtained in step (4) is graded and re-grinded and then fed into the reselection process to obtain gold concentrate II and final tailings.

2. The method for recovering copper, gold and iron from high-silicon, high-mud copper-gold ore according to claim 1, wherein: The copper grade in the ore is 0.7-1.2%, the gold grade is 1.5-3.0g / t ore, the copper oxidation rate is 50-90%, the native mud content is 15-40%, and the gangue minerals are chlorite, talc, tremolite and mica.

3. The method for recovering copper, gold and iron from high-silicon, high-mud copper-gold ore according to claim 1, wherein: In step (3) copper oxide flotation, the dispersant composition and mass ratio are propylene glycol: sodium hexametaphosphate: CMC = 3 parts: 4 parts: 3 parts; the vulcanizing agent is: one of sodium sulfide, sodium hydrosulfide, Na2S4 or a mixture of several of them in any ratio; the collecting agent is: one of amyl xanthate, isoamyl xanthate, butyl ammonium black medicine or a mixture of several of them in any ratio; the foaming agent is: one of 2# oil, MIBC, kerosene, diesel or a mixture of several of them in any ratio.

4. The method for recovering copper, gold and iron from high-silicon, high-mud copper-gold ore according to claim 1, wherein: In step (3), the amounts of dispersant, vulcanizing agent, ammonium sulfate, collector and foaming agent are 600-1000 g / t, 1-3 kg / t, 1-3 kg / t, 200-500 g / t and 5-30 g / t respectively.

5. The method for recovering copper, gold and iron from high-silicon, high-mud copper-gold ore according to claim 1, wherein: The reselection operation in step (5) is one or more of shaking table, spiral chute, Nelson, etc.

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