Method for pre-oxidizing refractory high-sulfur gold ore by ultrasonic activation of persulfate
阅读说明：本技术 一种超声活化过硫酸盐预氧化难处理高硫金矿的方法 (Method for pre-oxidizing refractory high-sulfur gold ore by ultrasonic activation of persulfate ) 是由 张利波 贵琪皓 王仕兴 胡玉婷 狄浩凯 梁明 吴邦建 于 2021-09-13 设计创作，主要内容包括：本发明涉及一种超声活化过硫酸盐预氧化难处理高硫金矿的方法,属于金矿处理技术领域。本发明将浮选后的高硫金矿破碎细磨至粒径为150目以下得到金矿粉；将金矿粉和过硫酸盐加入到水中混合均匀得到矿浆A；在室温、搅拌条件下,矿浆A经超声波强化活化预处理1～8h,固液分离,固体经洗涤、烘干得到预处理金矿粉；预处理金矿粉和氰化钠加入到水中混合均匀得到矿浆B,矿浆B中通入空气并在温度为20～50℃、搅拌条件下进行超声波强化浸出4～18h得到金浸出液和浸出渣,其中超声波强化浸出过程中体系的pH值为10.5～11.5。本发明利用超声波活化过硫酸盐释放过强氧化性的硫酸根自由基氧化难处理金矿中的硫化物包裹体,在预处理过程中去除阻碍金浸出的硫化物,以提高金浸出率。(The invention relates to a method for ultrasonically activating persulfate to preoxidize refractory high-sulfur gold ore, belonging to the technical field of gold ore treatment. Crushing and finely grinding the high-sulfur gold ore subjected to flotation until the particle size is below 150 meshes to obtain gold ore powder; adding gold ore powder and persulfate into water, and uniformly mixing to obtain ore pulp A; carrying out ultrasonic wave reinforced activation pretreatment on the ore pulp A for 1-8 h at room temperature under the stirring condition, carrying out solid-liquid separation, and washing and drying the solid to obtain pretreated gold ore powder; adding pretreated gold ore powder and sodium cyanide into water, uniformly mixing to obtain ore pulp B, introducing air into the ore pulp B, and carrying out ultrasonic enhanced leaching for 4-18 hours at the temperature of 20-50 ℃ under the stirring condition to obtain gold leaching liquid and leaching residues, wherein the pH value of the system in the ultrasonic enhanced leaching process is 10.5-11.5. According to the invention, the sulfide inclusion in the gold ore which is difficult to treat is oxidized by using the sulfate radical with strong oxidability released by activating persulfate through ultrasonic waves, and the sulfide which hinders gold leaching is removed in the pretreatment process, so that the gold leaching rate is improved.)
1. A method for pre-oxidizing refractory high-sulfur gold ore by ultrasonic activation persulfate is characterized by comprising the following specific steps:
(1) crushing and finely grinding the high-sulfur gold ore subjected to flotation until the particle size is below 150 meshes to obtain gold ore powder; wherein the sulfur content in the high-sulfur gold ore is 5-30%;
(2) adding gold ore powder and persulfate into water, and uniformly mixing to obtain ore pulp A;
(3) carrying out ultrasonic wave reinforced activation pretreatment on the ore pulp A for 1-8 h at room temperature under the stirring condition, carrying out solid-liquid separation, and washing and drying the solid to obtain pretreated gold ore powder;
(4) adding pretreated gold ore powder and sodium cyanide into water, uniformly mixing to obtain ore pulp B, introducing air into the ore pulp B, and carrying out ultrasonic enhanced leaching for 4-18 hours at the temperature of 20-50 ℃ under the stirring condition to obtain gold leaching liquid and leaching residues, wherein the pH value of the system in the ultrasonic enhanced leaching process is 10.5-11.5.
2. The method of claim 1 for the ultrasonic activation of persulfate pre-oxidation refractory high-sulfur gold ore, which is characterized in that: the solid-liquid ratio g/mL of the gold ore powder to water in the step (2) is 1: 2-6, and the concentration of persulfate in the ore pulp A is 80-200 g/L.
3. The method of claim 1 for the ultrasonic activation of persulfate pre-oxidation refractory high-sulfur gold ore, which is characterized in that: and (3) stirring speed is 200-600 rpm, ultrasonic frequency is 20-40 kHz, and ultrasonic power is 500W-1 kW.
4. The method of claim 1 for the ultrasonic activation of persulfate pre-oxidation refractory high-sulfur gold ore, which is characterized in that: the solid-liquid ratio g/mL of the pretreated gold ore powder to water in the step (4) is 1: 2-1: 4, the addition amount of sodium cyanide is 2-10 kg/t based on the pretreated gold ore powder, the air flow is 50-200L/h, the ultrasonic power is 200-800W, and the ultrasonic frequency is 20-40 kHz.
Technical Field
The invention relates to a method for ultrasonically activating persulfate to preoxidize refractory high-sulfur gold ore, belonging to the technical field of gold ore treatment.
Background
The high-sulfur refractory gold concentrate is used as the refractory high-sulfur gold ore type with the largest proportion, gold is mainly wrapped in sulfide, and the main wrapping object phases are pyrite and arsenopyrite. Such sulphides hinder the contact of the leaching agent with gold during leaching, while consuming the leaching agent; but also form a passivation layer that further hinders leaching. In order to solve the problem that the gold concentrate which is difficult to treat is difficult to leach, the purpose of removing sulfide is achieved by using an oxidation calcination method at present, but a large amount of greenhouse gas is generated by the method, and simultaneously arsenic is volatilized along with the greenhouse gas, so that the problem of great environmental pollution is caused. The chemical oxidation method is to oxidize the inclusion to destroy the inclusion, and potassium permanganate, sodium hypochlorite and the like are commonly used. But because the reagent is expensive and the oxidation rate is slow, the industrial production requirement is difficult to achieve.
Disclosure of Invention
Aiming at the problem that gold in gold concentrate which is high in sulfur and difficult to treat is difficult to leach in the prior art, the invention provides a method for pre-oxidizing high-sulfur gold ore by ultrasonically activating persulfate, namely persulfate is used as an oxidant, and the persulfate is promoted to release persulfate (SO) with strong oxidizing property by ultrasonic activation4 ·—) The oxidation effect of the sulfide inclusion is improved; meanwhile, the mechanical effect, the thermal effect and the cavitation effect of the ultrasonic are utilized to improve the mass transfer efficiency of the solution, promote the reaction process, destroy the inclusion, reduce the granularity of the ore and improve the subsequent leaching efficiency.
A method for pre-oxidizing refractory high-sulfur gold ore by ultrasonic activation persulfate comprises the following specific steps:
(1) crushing and finely grinding the high-sulfur gold ore subjected to flotation until the particle size is below 150 meshes to obtain gold ore powder; wherein the sulfur content in the high-sulfur gold ore is 5-30%;
(2) adding gold ore powder and persulfate into water, and uniformly mixing to obtain ore pulp A;
(3) carrying out ultrasonic wave reinforced activation pretreatment on the ore pulp A for 1-8 h at room temperature under the stirring condition, carrying out solid-liquid separation, and washing and drying the solid to obtain pretreated gold ore powder;
(4) adding pretreated gold ore powder and sodium cyanide into water, uniformly mixing to obtain ore pulp B, introducing air into the ore pulp B, and carrying out ultrasonic enhanced leaching for 4-18 hours at the temperature of 20-50 ℃ under the stirring condition to obtain leachate and leaching residues, wherein the pH value of the system in the ultrasonic enhanced leaching process is 10.5-11.5.
The solid-liquid ratio g/mL of the gold ore powder to water in the step (2) is 1: 2-6, and the concentration of persulfate in the ore pulp A is 80-200 g/L;
the stirring speed in the step (3) is 200-600 rpm, the ultrasonic frequency is 20-40 kHz, and the ultrasonic power is 500W-1 kW;
the solid-liquid ratio g/mL of the pretreated gold ore powder to water in the step (4) is 1: 2-4, the addition amount of sodium cyanide is 2-10 kg/t based on the pretreated gold ore powder, the air flow is 50-200L/h, the ultrasonic power is 200W-800W, the ultrasonic frequency is 20 kHz-40 kHz, and the stirring speed is 300-700 rpm.
The invention has the beneficial effects that:
(1) the invention uses persulfate as an oxidant, activates the persulfate by using ultrasound, and promotes the persulfate to release sulfate radicals (SO) with strong oxidizing property under the action of the ultrasound4 ·—) Oxidizing the sulfide inclusion;
(2) the ultrasonic reinforcement of the invention not only can shorten the reaction time, but also can improve the pretreatment and leaching effects of the gold ore, the ore is crushed in the ultrasonic process, the coated gold is exposed, and the granularity of the ore can be reduced by 20-50% compared with that before the ultrasonic treatment; the pretreatment and leaching of gold ore are greatly strengthened under the action of ultrasonic waves.
Detailed Description
The present invention will be described in further detail with reference to specific embodiments, but the scope of the present invention is not limited to the description.
Example 1: in the refractory gold concentrate of the embodiment, the gold grade is 35.23g/t, the leaching rate of gold leached by conventional direct cyanidation is only 49.1 percent, the consumption of pyrite in sulfide is 34.52 percent, the content of arsenopyrite is 4.77 percent, and the average particle size is 33.75 mu m;
a method for pre-oxidizing refractory high-sulfur gold ore by ultrasonic activation persulfate comprises the following specific steps:
(1) crushing the refractory high-sulfur gold concentrate subjected to flotation to more than 150 meshes to obtain gold sulfide concentrate powder; wherein the sulfur content in the gold sulfide concentrate powder is 20.41 percent;
(2) adding the refractory gold concentrate powder obtained in the step (1) and sodium persulfate into water, and uniformly mixing to obtain gold ore pulp; wherein the solid-to-liquid ratio g: ml of the refractory gold concentrate to water is 1:4, and the content of sodium persulfate in the refractory gold concentrate is 80 g/L;
(3) performing ultrasonic wave reinforcement pretreatment for 4 hours under the stirring condition at the gold ore pulp temperature of 20 ℃, performing solid-liquid separation, and washing and drying solids to obtain pretreated gold ore powder; wherein the stirring speed is 400rpm, the ultrasonic frequency is 20.0kHz, the power is 480W, the removal rate of the pretreated pyrite is 57.24 percent, the removal rate of the arsenic pyrite is 46.09 percent, and the average granularity of the gold ores is reduced to 27.24 mu m;
(4) adding the pretreated gold ore powder and sodium cyanide into water, uniformly mixing, introducing air, and carrying out ultrasonic enhanced leaching for 8 hours under the stirring condition to obtain a gold leaching solution and leaching residues, wherein the stirring speed is 500 rpm, the temperature of the ultrasonic enhanced leaching is 25 ℃, the pH value is 11 +/-0.5, the solid-to-liquid ratio g: mL of the pretreated gold ore powder to the water is 1:4, the addition amount of the sodium cyanide is 4kg/t based on the pretreated gold ore powder, the air flow is 120L/h, the ultrasonic power is 500W, and the ultrasonic frequency is 20 kHz;
the gold leaching rate of this example was 65.41%.
Example 2: for a certain refractory gold ore, the gold grade is 27.5 g/t, the gold leaching rate obtained by the direct conventional cyanidation leaching process is only 49.1 percent, the pyrite content is 47.24 percent, the arsenic pyrite content is 9.52 percent, and the average particle size is 42.70 mu m;
a method for pre-oxidizing refractory high-sulfur gold ore by ultrasonic activation persulfate comprises the following specific steps:
(1) crushing the refractory gold ore subjected to flotation to more than 150 meshes to obtain gold sulfide concentrate powder; wherein the sulfur content in the gold sulfide concentrate powder is 27.05 percent;
(2) adding the refractory gold concentrate powder obtained in the step (1) and ammonium persulfate into water, and uniformly mixing to obtain gold ore pulp; wherein the solid-to-liquid ratio g: ml of the refractory aurin ore concentrate to water is 1:6, and the ammonium persulfate in the refractory aurin ore concentrate is 180 g/L;
(3) performing ultrasonic wave reinforcement pretreatment for 3 hours under the stirring condition at the gold ore pulp temperature of 25 ℃, performing solid-liquid separation, and washing and drying solids to obtain pretreated gold ore powder; wherein the stirring speed is 600rpm, the ultrasonic frequency is 30.0kHz, the power is 800W, the removal rate of the pretreated pyrite is 72.52 percent, the removal rate of the arsenic pyrite is 64.24 percent, and the average particle size is reduced to 17.24 mu m;
(4) adding the pretreated gold ore powder and sodium cyanide into water, uniformly mixing, introducing air, and carrying out ultrasonic enhanced leaching for 12 hours under the stirring condition to obtain a gold leaching solution and leaching residues, wherein the stirring speed is 300rpm, the temperature of the ultrasonic enhanced leaching is 40 ℃, the pH value is 11 +/-0.5, the solid-to-liquid ratio g: mL of the pretreated gold ore powder to the water is 1:3, the addition amount of the sodium cyanide is 9 kg/t based on the pretreated gold ore powder, the ultrasonic power is 800W, and the ultrasonic frequency is 28 kHz;
the gold leaching rate of this example was 93.52%.
Example 3: for a certain refractory gold ore, the gold grade is 14.63 g/t, the gold leaching rate obtained by the direct conventional cyanidation leaching process is only 24.74 percent, the pyrite content is 27.73 percent, the arsenic pyrite content is 14.56 percent, and the average particle size is 62.95 mu m;
a method for pre-oxidizing refractory high-sulfur gold ore by ultrasonic activation persulfate comprises the following specific steps:
(1) crushing the refractory gold ore powder subjected to flotation to more than 150 meshes to obtain gold sulfide concentrate powder; wherein the sulfur content in the gold sulfide concentrate powder is 17.64;
(2) adding the refractory gold concentrate powder obtained in the step (1) and calcium persulfate into water, and uniformly mixing to obtain gold ore pulp; wherein the solid-to-liquid ratio g: ml of the refractory gold concentrate to water is 1:2, and the concentration of calcium persulfate in the refractory gold concentrate is 110 g/L;
(3) performing ultrasonic wave reinforcement pretreatment for 7 hours under the stirring condition at the gold ore pulp temperature of 30 ℃, performing solid-liquid separation, and washing and drying solids to obtain pretreated gold ore powder; wherein the stirring speed is 300rpm, the ultrasonic frequency is 40.0kHz, the power is 1000W, the removal rate of the pretreated pyrite is 61.42%, the removal rate of the arsenic pyrite is 57.88%, and the average particle size is reduced to 38.44 μm;
(4) adding the pretreated gold ore powder and sodium cyanide into water, uniformly mixing, introducing air, and carrying out ultrasonic enhanced leaching for 16 hours under the stirring condition to obtain a gold leaching solution and leaching residues, wherein the stirring speed is 700 rpm, the temperature of the ultrasonic enhanced leaching is 30 ℃, the pH value is 11 +/-0.5, the solid-to-liquid ratio g of the pretreated gold ore powder to the water is 1:2, the addition amount of the sodium cyanide is 6 kg/t based on the pretreated gold ore powder, the ultrasonic power is 600W, and the ultrasonic frequency is 40 kHz;
the gold leaching rate of this example was 83.52%.
While the present invention has been described in detail with reference to the specific embodiments thereof, the present invention is not limited to the embodiments described above, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art.