The flotation reagents of oxidized ore can classify the flotation collectors of copper oxide minerals in the following categories according to the different flotation methods:
(1) xanthate and its derivatives; (2) alkyl oxygen acid (salt) class; (3) other comprehensive classes.
One, xanthate and its derivatives
So far, sulphide xanthate flotation is the main way to choose oxidized copper ore. Xanthate is the main collector of oxidized copper ore, or it is a mixture of xanthate collector and other collector.
The xanthate collector used in most of the copper oxide selection plants in China is n-butyl xanthate.
In order to meet the needs of all kinds of ores for other types of xanthate, relevant departments have also done research work in this field, such as isobutyl xanthate, isoamyl xanthate and mixed xanthate. In many cases, these drugs can replace n-butyl xanthate, and also have some advantages.
The performance of isobutyl xanthate is similar to that of n-butyl xanthate, but it is more stable and more selective than n-butyl xanthate. There are many domestic and foreign plant using isobutyl xanthate as collector agent to do some tests, such as the Hongtoushan Copper Mine using isobutyl xanthate dosage by 20g/t, the ratio of butyl xanthate, two oil decreased by 5.5g/t, and the rate under the same grade of copper concentrate increased 1.2% in Baifang copper mine recovery; isobutyl xanthate after use, the grade of copper concentrate increased by 2.25%, increasing the recovery rate of 0.3%.
Secondary octyl xanthate is also reported as a collector of copper oxide minerals. The collector has a strong collecting capacity for copper oxide minerals, and has a certain foaming property, which can reduce the amount of the foaming agent.
Two, alkyl oxygen acid and its salts
This kind of collector usually contains oxygen, nitrogen and other atoms in its polar group. At the same time, the molecular weight of the non polar group is large, which belongs to the anionic collector.
(1) the application of carboxylic acids. In the early flotation of copper oxide minerals, many fatty acids (such as sodium oleate and palmitic acid) were used as collectors to direct flotation. However, as the source of fatty acids is limited and the amount is large, it is gradually replaced by other collectors in the flotation of copper oxide minerals.
At the end of 1970s, the synthetic fatty acids from C5 to C9 or C7 to C9 were used for the production of silicon malachite and copper oxide ore flotation.
In recent years, many methods have been studied at home and abroad to improve their properties, and a series of related collectors have been obtained. Some of them have the ability to improve the flotation results of fatty acid collectors, namely the so-called fatty acid synergist. However, the application of fatty acid collectors in the flotation of copper oxide ores is still less.
(two) sulfonic acid (salt) and sulphate ester. This kind of collector is bubbling and sometimes used as a foaming agent. As a collector, its selectivity is stronger.
The flotation of pure minerals of peacock was studied by using sodium alkyl sulfate and sodium alkyl sulfonate (twelve alkyl sulfonate), and the collection performance of sodium oleate was compared with that of sodium oleate. The results showed that twelve sodium alkyl sulfate and twelve alkyl sulfonate had strong collecting effect on Malachite and wide flotation pH range, and had the same collecting property with sodium oleate. Because twelve alkyl sulfate and twelve alkyl sulfonate have less ability to collect calcium minerals than sodium oleate, they have better selectivity and can be used in hard water, which is superior to sodium oleate.
(three) phosphonic acid. The main varieties of phosphonic acid collector used in flotation of copper oxide ore are alkyl phosphonate and two alkyl phosphonic acid (R2PO2H, R are octyl, Zhong Xinji, ethyl, cycloethyl and phenyl) respectively.
Two alkyl phosphonic acid is a new type of flotation collector for copper oxide ores. The results show that two alkyl phosphonic acid is an effective collector for fine malachite. The collecting performance was reduced by two ethyl hypophosphonic acid > two octyl phosphonic acid > two secondary octyl phosphonic acid > cyclohexyl phosphonic acid > two phenyl hypophosphite. For the mashed malachite, the suitable agent is two ethyl phosphonic acid (total carbon number is 11~12).
(four) oxime acid. Hydroxamic acid (or hydroxamic acid) N, acyl derivatives of hydroxylamine, the enol tautomer is hydroxamic acid:
Their Cu2 + reaction produces a chelate that is difficult to dissolve in water.
At present, alkyl oxime sodium is widely used, and the preparation of sodium oximate has different methods. The synthesized C5 ~ 9 and C7 ~ 9 alkyl hydroxamic acid natrium were hydrolyzed to prepare hydroxylamine sulfate by using lower sand alkane, then reacted with the same synthetic male ester of hydroxy acid. The liquid hydroxamic acid sodium product with an effective component of 30% was obtained directly without acidification and saponification.
The factors affecting the flotation process of oxime collectors include the pH value of the pulp, the use of collectors, the necessity of precuring and the role of the gangue.
The study of copper oxide ore shows that the best flotation effect can be obtained at about pH=9. The reason is that the pK value of hydroxamic acid is 9.5. Therefore, at pH=9, the ionic state of hydroxamic acid and the CO adsorption of molecules on the mineral surface may play a major role in the recovery of magnetic minerals.
Although the collecting ability of oxime acid (sodium) is very strong, the single use of oxime acid (sodium) can not get a good flotation effect. A large number of studies have shown that the mixed use of oxime acid (sodium) and xanthate is much better than the separation of xanthate or oxime acid (sodium) alone. The use of C5 ~ 9 and ~ 9 C7 mixed drug results alkylhydroxamic acid and sodium butyl xanthate, the recovery rate of ore dressing plant is increased by 5% or more, all the original with the consumption of flotation reagents have different degrees of decline, lime, 2 oil consumption is reduced by half, sodium sulfide, butyl xanthate dosage also decreased by nearly 1/5. The flotation rate and foam fluidity are greatly improved, and the operating conditions are improved. In addition, a proper amount of neutral oil (such as diesel oil) is added. It can improve the foam properties of oxime acid (sodium) flotation, which can reduce the yield of concentrate and improve the quality of concentrate.
Because sodium oxalate can float calcium and magnesium carbonate minerals, it is also an important factor to effectively inhibit the use of sodium six phosphate in flotation of calcium and magnesian oxidized copper ores. At the same time, the addition of ammonium sulfate and water glass can improve the selectivity of the flotation process without affecting the flotation of copper ore.