Survey of research on fine-grained cassiterite flotation reagent

Of tin ore is rich in resources, mainly in Yunnan, Guangxi, Hunan, Inner Mongolia, Guangdong and Jiangxi provinces, of which Yunnan old is known as China's "tin can." The main raw material for tin is cassiterite. The cassiterite is a dense, brittle mineral that is easily broken into fine particles during the mining process. For large particle cassiterite, it is generally recovered by re-election method; for fine-grained cassiterite, the recovery rate of re-election is low, and it is generally recovered by flotation method or combined method. There are many kinds of agents for flotation of cassiterite, but there are technical problems of poor selectivity, high cost and low index. Therefore, there are a lot of researches on collectors and inhibitors of cassiterite flotation at home and abroad, and many research results have been obtained. .

First, cassiterite flotation collector

(1) Common collectors

Industrial use of cassiterite collectors are mainly fatty acids, swollen acid, alkyl hydroxamic acid, alkyl sulfosuccinic acid, phosphonic acid 5, oleic acid, benzyl sulphonic acid, A-22, salicylox Acid is a commonly used collector.

1, fatty acid collector

This is a common collector flotation agent for oxidized ore, titanium oxide ore recovered in the iron ore, diamond ore zinc has been widely used.

Oleic acid is the most common fatty acids in a collector, which collector received strong ability, the amount is small, non-toxic, but poor selectivity for Fe ^{3 +,} Ca ^{2 +} sensitive to iron minerals, fluorite, calcite It has a strong ability to collect and is generally used for flotation of cassiterite- quartz type slime under neutral or alkaline conditions.

Aliphatic phosphoric acid collector suitable for free Fe ^{3 +} and Pb ^{2 +} ore flotation, generally in an amount of 1000 ~ 1500 g / t, pH optimum value is between 2.55 to 3.50.

2. Tannic acid collector

Tannic acid is classified into aromatic tannic acid and aliphatic tannic acid, and is a more effective collector.

Arsenic is preferably an aromatic acid flotation in acid medium, but toxic, harmful. The order of the ability to collect fine-grained cassiterite is: mixed tolonic acid > p-toluene acid > benzyl decanoic acid > o-toluene citrate; in weakly acidic and neutral pulp, mixed toluene citrate flotation tin Stone works best. Use it flotation gold mud containing tin sulfide minerals, to avoid the influence of sludge, desliming be pre-processed, and to avoid the influence of tin sulphide concentrates on the quality, to be pre-desulfurization. The use of Y89 xanthate desulfurization to the bismuth polymetallic sulfide ore is better, and the sulfur removal effect is better, which creates conditions for the flotation of cassiterite.

Aliphatic citric acid is a good collector, which can react with metal ions such as Sn ^{2 +} , Sn ^{4 +} and Fe ^{3 +} to form poorly soluble compounds. When the concentration is high, it can react with Ca ^{2 +} and Mg ^{2 +} to form salt.

The ore processed by the Barry Plant is a cassiterite polymetallic sulfide ore. The sulfide minerals include iron sphalerite, pyrrhotite, arsenopyrite, etc., and the gangue minerals are quartz and calcite. The flotation of cassiterite is sulfuric acid, benzyl arsenate, P86, sodium carboxymethylcellulose and No. 2 oil, which can increase the concentrate grade by 4.68% before the improvement of the pharmaceutical system.

3, alkyl hydroxamic acid

These collectors are more selective than fatty acids and less toxic than arsenic acids, but their ability to capture is relatively weak, large in dosage, and high in price. Under the premise of achieving the same effect, they are generally used to replace arsenic acid. Collecting agent.

The most commonly used alkyl hydroxamic acid is salicyl hydroxamic acid. In the weakly alkaline medium, TBP has a strong trapping effect when used as an auxiliary collector. In 1999, when the Chehe Concentrator improved the collector, the new combination of salicyl hydroxamic acid and P86 was used instead of the swelling acid collector. As a result, the recovery rate of the cassiterite operation was increased by 2.24%, and the enrichment ratio was improved. It is 0.5 times and the dosage is half of the original collector, which greatly reduces the production cost.

In 2003, Zhu Jianguang experimented with the ore samples from Chehe, and proved that 1-hydroxy-2-naphthoquinone (H ₂₀₃ ) and its isomer 2-hydroxy-3-naphthoquinone (H ₂₀₅ ) is a good collector of cassiterite. Among them, H ₂₀₅ can obtain tin saponin with a grade of 18.29% and a recovery rate of 92.68% from the closed-circuit test of ore feeding with particle size less than 11μm and 76% and tin grade of 1.16%. mine.

4, alkyl sulfosuccinic acid collector

These medicinal agents have strong harvesting capacity, low dosage, low price, non-toxicity and short duration of action with minerals. They are widely used in cassiterite flotation plants in Bolivia, the United Kingdom, the former Soviet Union and Peru.

Sulfonated carbamide acid has a better flotation effect on coarse-grained cassiterite and is the most widely used. Flotation of cassiterite with sodium sulfosuccinate, the amount is generally 500-800g / t, pH is 3.5-4.3, adding Aqua-mollin BC (ethylenediaminetetraacetic acid tetrasodium salt) complex high-iron ion and water glass dispersion Fine-grained gangue particles can obtain better flotation indicators.

Sulfobinic acid has good collection performance for fine-grained cassiterite, low dosage, fast flotation speed, but poor selectivity, and is suitable for use in acidic medium. The same kind of agent also has sulfosuccinic acid (N-octadecylsulfonated succinamide disodium salt, domestic code A-18), A-22,209 detergent and the like. A-18 is both a cassiterite collector and a slime dispersant. It has foaming properties and has a catching effect on sulphide ore. A-22 is suitable for application in weakly acidic medium, with strong harvesting ability, low dosage, fast action, no toxicity, and the best effect when pH is around 6.

5, linic acid collector

Phosphonic acids are classified into aromatic phosphonic acids and aliphatic phosphonic acids.

The aromatic phosphonic acid has strong ability to capture and select good cassiterite. Styrylphosphonic acid is more commonly used, its harvesting capacity and selectivity are better than oleic acid. It can be used in weak acid and neutral pulp. It has good index and low price. It can be used for flotation of cassiterite, wolframite , rutile, etc. . The industrial test of styrene-phosphonic acid flotation of Huangmaoshan tin-containing fine mud has achieved good results. The grade of tin concentrate is 24.26%-26.4%, and the recovery rate is 44.79%~52.14%.

Aliphatic phosphonic acids (C ₆ ~ C ₈₎ strong collecting capability, with less weak selectivity for Ca ^{2 +,} Fe ^{3 +} sensitive, not sticky and froth concentrate is easily dispersed, it can be weakly acidic and neutral Flotation in the slurry.

(2) Other types of catching

Alkyl phosphate collectors are less toxic, generally have good collection and selectivity, and have good resistance to hard water in weakly alkaline media and at room temperature. A tin ore selection plant in India uses alkylphosphonate as a collector, sodium silicate as an inhibitor, sulfuric acid and citric acid as a pH adjuster. After a coarse and two fine flotation, the tin mass fraction is 0.24%. A tin concentrate with a grade of 7% and a recovery rate of 55% was obtained from the re-selected tailings.

Alkyl sulfate sodium salt (C ₁₂ ~ C ₂₀ "for collecting capability than oleic cassiterite weak, selective collecting capability of brass ore, pyrite collectors weak, calcium-containing minerals The selectivity is good, and the general dosage is 20-30 g/t.

Amine collectors are preferred collectors for sulphur flotation, which include primary amine salts, secondary amine salts, tertiary amine salts, quaternary ammonium salts and alkyl pyridinium salts, of which primary amine salts are widely used.

Tongtieling has better ability to capture cassiterite than methotrexate. The use of copper iron spirit floatation of cassiterite fine mud can obtain better indicators, but because of the large amount, it is often mixed with benzoic acid, and the synergistic effect of the two agents can be used to reduce the dosage and obtain a good float. Selected indicators.

(3) New type of capture

Although there are many kinds of existing traps, there are still some problems, such as high cost, polluted environment, and difficult processing of fine-grained grades. Therefore, in recent years, many new collectors have been developed at home and abroad, such as ZJ-3, BY. -9, CF, SR, etc.

ZJ-3 is a successful new collector for Zhu Yimin and other research constitutions. The agent is highly toxic and low-toxic, and is suitable for treating fine-grained cassiterite having a degree of less than 19 μm. ZJ-3, auxiliary collector TBP and inhibitor CMC were selected by Chehe Plant for a coarse, two-precision and one-sweep flotation. The grades were selected from the ore with a mass fraction of 1.16%, and the grades were recovered by l8, 29%. Rate 92. 68% tin concentrate.

BY-9 is a chelating collector of cassiterite, Ren Jizhen, etc., and recovers tin from flotation of cassiterite polymetallic sulphide ore tailings. By comparing the flotation effects of BY-9, C9 hydroxamic acid and Sun 2#, BY-9 has the best collection effect, and the dosage is 1000g/t. Adding 100 g/t of the effective promoter P86 for collecting cassiterite and 50-100 g/t inhibitor BY-5 and 50 g/t2 ^# oil, finally obtaining a concentrate with a grade of 48.76% and a recovery rate of 49.88%. The floatability of cassiterite and silicate is equivalent. When Mengzi Mining & Metallurgy Co., Ltd. handles tailings, BY-9 is used as collector, P86 is auxiliary collector, sodium carbonate and BY-5 are inhibitors ( The main component is the essence), and a tin concentrate with a tin grade of 53.58% and a recovery rate of 50.12% is obtained.

CF is a new type of chelating collector developed by Beijing Research Institute of Mining and Metallurgy. It is suitable for flotation of cassiterite and strontium minerals. It has strong ability to capture cassiterite and has good selectivity, and has good application prospects.

SR is a new type of high-efficiency collector for fine-grained cassiterite. For the ore of No. 100 (105) ore body, the agent is used to assist the collector P86, which can achieve the concentrate grade and operation recovery rate of 11.43 respectively. % and 88.72%.

Second, cassiterite flotation inhibitor

(1) Inorganic inhibitors

Common inorganic inhibitors are water glass, fluorosilicic acid, sodium fluorosilicate, sodium fluoride, sodium sulfide, sodium hexametaphosphate and the like.

Waterglass used to suppress silicate mineral cassiterite flotation when it cassiterite, calcite, fluorite, barite, zircon, scheelite, galena, calcium tungsten and molybdenum ore, gypsum, boric acid Salt, chlorite, chin iron ore, cinnabar and vermiculite have different degrees of inhibition, but the critical amount of inhibition is different. In addition, water glass also has an inhibitory effect on copper sulfate and lead acetate-activated quartz, mainly due to the formation of copper silicate and lead silicate compounds in the slurry. When metal ions (such as Al ^{3 +} , Cu ^{2 +} , Pb ^{2 + ,} etc.) are appropriately added to the slurry, the effect of the water glass can be enhanced. In addition, water glass, sodium carbonate, and sodium hydroxide can be used as pH adjusters for cassiterite flotation.

Fluosilicic acid, sodium fluoride and sodium fluoride are potent inhibitors of the fluorine-containing mineral containing aluminum, often used in conjunction with styrene phosphonic acid. With an alkyl sulfate, A-22, styrene phosphonic acid cassiterite flotation, the pulp Ca ^{2 +,} Fe ^{3 +} and so would inhibit cassiterite. In order to reduce this inhibition, a certain amount of sodium fluorosilicate is often added.

In addition, sodium sulphide and sodium hexametaphosphate are also good inhibitors of sulphur flotation. Under basic conditions, when the flotation of cassiterite oleic acid, sodium sulfide can be suppressed in Pb ^{2 +,} Cu ^{2 +} activated silica, but do not inhibit cassiterite. Similarly, when sodium hexametaphosphate and oleic acid are used in combination, calcite and limonite in the gangue can be suppressed.

(2) Organic inhibitors

Preferred organic inhibitors for flotation of cassiterite are sodium hydroxymethylcellulose, tributyl phosphate, naphthol sulfonic acid, high molecular weight oxalic acid, oxalic acid, straw cellulose, pyrogallol, calcium lignosulfonate (GF), citric acid, lactic acid, tannin, starch, dextrin, tartaric acid EDTA, and the like.

Hydroxymethyl fiber is a potent inhibitor of calcite. It can be used in combination with oleic acid, mixed toluene acid, and Aerosol-22. It has obvious inhibitory effects on gangue minerals such as calcite. When sodium carboxymethylcellulose is used in combination with oleic acid and the pH is 8.1, the inhibition of the calculus is the strongest. Tributyl phosphate is expensive and is often used with sodium carboxymethylcellulose. Naphthol sulfonic acid is a potent inhibitor of topaz and is often used in combination with alkyl dicarboxylic acids. Ammonia is a good inhibitor of tourmaline . Oxalic acid and sulfites are potent inhibitors of iron-containing minerals, iron, manganese and minerals commonly oxalate inhibition gangue. Straw cellulose has a strong inhibitory effect on cassiterite, calcite, quartz, etc. When hematite contains hematite and pH=3, pyrogallol has a strong inhibitory effect on hematite. For refractory cassiterite, the separation of cassiterite and hematite with A-22 and pyrogallol is effective. GF is an organic inhibitor, and has a strong inhibitory effect on gangue minerals such as calcite and quartz. The dosage is generally 100-200 g/t. In addition, GF, SR, and P86 are the best combination agents for Barry Tin fine mud.

Third, the effect of metal cations on the performance of the collector

(a) The impact of Fe ^{3 +}

Fe ^{3 +} in the pulp has an inhibitory effect on gangue and cassiterite. Using aliphatic phosphonic acid as a collector, Fe ^{3 +} has the strongest inhibitory effect on cassiterite at pH <4.5. When harvested with sodium sulfosuccinate, Aquamollin BC can counteract the effect of 10 mg/L iron at pH=3. When flocculant is floated with collector A-22, Fe ^{3 +} has little effect on A-22 flotation of cassiterite at a concentration of less than 10 ^-4 mol/L, but with increasing concentration, cassiterite Will be strongly inhibited.

(B) Ca ^{2 +} impact

When the collector is oleic acid, a small amount of Ca ^{2 +,} have activation of cassiterite.

(3) The impact of A1 ^{3 +}

A1 ^{3 +} significantly affects the flotation of cassiterite by sulfonated succinic acid acid collector. When A1 ^{3 + is used} together with A-22, para-toluene arsenate and dodecyl acetate, Al ^{3 +} has a certain inhibitory effect on cassiterite. When A1 ^{3 +} is added simultaneously with p-toluene arsenate, and the pH is 2 to 4, Al ^{3 +} has an activation effect on cassiterite.

(4) The impact of Pb ^{2 +}

Pb ^{2 +} has a certain activation effect on the flotation of cassiterite when using aliphatic phosphonic acid as a collector.

Further, when used as collector ^{CF, Ca 2 +, Mg 2} +, Cu 2 +, Zn 2 +, 3 +, Sn 4 + are inhibited from cassiterite, tantalum and niobium mineral Fe, Cu ^{2 +} in which , Fe ^{3 +} , Sn ^{4 +} has a greater impact.

Fourth, the conclusion

The difficulty in sorting fine-grained cassiterite is still a major problem in the mineral processing industry. Although the flotation method is one of the most effective methods for recovering fine-grained cassiterite, the cost of cassiterite flotation reagent is high, the environmental pollution is large, and the index is low. Therefore, research and development of new pharmacy and combination agent on fine cassiterite The recycling is important.

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