The mechanism of action of BOP hydroxamic acid is discussed below:

BOP hydroxamic acid is a new type of isomer hydroxamic acid. Its group capable of coordinating with metal ions is hydroxyl group (-OH) and mercapto group (=NOH), in which the hydroxyl group is mostly in undissociated form. Paired with metal ions, but under certain conditions, it can also be coordinated with metal ions in the form of lost protons (-O-); the coordination form of sulfhydryl groups is more numerous: it can be lost in the form of acidic groups The protons are coordinated to the metal ions by negatively charged oxygen (=NO-), and may also be coordinated to the metal ions by trivalent nitrogen in an undissociated form, or in the form of isomers = N. The action, such as an acidic group, coordinates the negatively charged nitrogen after the proton is lost to coordinate with the metal ion. It can form complex compounds in different ways in aqueous solution with various metal ions such as Cu, Co, Ni, Mo, Fe, etc., many of which form a chelate formed by two coordinating groups, hydroxamic acid and copper cobalt. The chelation forms the following chelated copper cobalt citrate:

Chelation capture mechanism

In the flotation system of copper oxide cobalt mineral-solution, a copper chelate can be formed on the surface of the copper mineral and precipitated at the mineral interface or precipitated in the aqueous solution. What is specifically formed depends on the solution chemistry of the entire flotation system. The formation of precipitates is also limited by the solubility of the copper chelate in solution, but the insoluble copper chelate is not necessarily hydrophobic. As a copper-cobalt mineral flotation collector, the copper-cobalt chelate formed on the surface or at the interface of the mineral should be sufficiently hydrophobic so that the mineral is fixed on the bubble. Theoretical studies have shown that the surface of copper-cobalt minerals and BOP hydroxamic acid react mainly by the following mechanisms: chemical adsorption, surface reaction and precipitation in solution.

(1) Chemical adsorption

In chemisorption, when combined with a donor atom in a collector functional group adsorbed on a mineral surface, they bind to a covalent or coordinate bond that does not leave the surface metal cation in the crystal lattice. Because each surface particle binds to a chelating agent molecule, adsorption is limited to a single layer.

(2) Surface chemical reaction

The reaction with the chelating collector to cause the metal cation to leave the original position of the crystal lattice to a position close to the surface of the mineral. This process involves the hydration of metal cations on the mineral surface. The hydration reaction may cause metal ions to leave the lattice position and participate in chelation with the added collector.

(3) Precipitation in solution

If the solution chemistry in the mineral flotation system is suitable for the dissolution of the mineral surface, which can chemically react with the collector to form a metal chelate or precipitate into the solution, precipitation in the solution may occur. . Of course, this reaction between the collector and the mineral will deplete the collector involved in the surface reaction. If the metal ion dissolution rate and the diffusion rate through the interface layer are higher than the rate at which the collector diffuses toward the mineral surface, a metal chelate precipitate is formed in the solution.

In fact, in flotation systems using BOP hydroxamic acid, chemisorption is most desirable. The adsorption of chelation is limited to a single layer, and the consumption of the collector is the least. Tests have shown that the amount of collector is not large, mainly because the carbon chain of the agent is long enough to form a hydrophobic reaction directly at the interface.

Combined collector co-adsorption mechanism

Due to the non-uniformity of the mineral surface and the uneven and incomplete vulcanization of the ore surface during the vulcanization process, there are different regions of complete vulcanization, incomplete vulcanization, and no vulcanization at all. This requires the use of a combination of collectors, the use of different electronegativity collectors to capture their respective active sites and play their respective roles, improve the overall hydrophobicity, thereby increasing the recovery rate of mineral processing metals. This is the synergistic effect produced by the combined collector. The specific process is as follows:

According to the valence bond theory, copper sulfide has a large covalent radius due to its small electronegativity. According to the theory of soft and hard acid and alkali, sulfur has low electronegativity and high polarizability, and should be easily oxidized. Their confinement of covalent electrons is also loose, so it belongs to a softer base, so it is Its joining atoms have an effect. The softness of the bonded atoms is increased, that is, the copper ions in the copper sulfide are softer acids. In copper oxide, due to the high electronegativity of oxygen, the polarization is low, and it is difficult to be oxidized, and its valence electrons are tightly bound. Thus, the alkali ion having a relatively hard oxygen ion has an electron-inducing effect, so that the hardness of the copper ion in the bond becomes large, that is, the copper ion in the copper oxide ore is an acid having a relatively high hardness. The vulcanized area or particle, because it is a soft acid, can be tightly bound to the softer xanthate. However, there is no vulcanized area or particle, so the hardness is large, easy to work with hard alkaline water, and the hydrophilicity is strong. In this part, the hydrocarbon group of the collector must be long enough to overcome the influence of hydration energy, so A chelating collector with a strong harvesting ability, such as BOP hydroxamic acid, must be used.

Generally, the amount of oxidizing ore collector is large and the selectivity is low. For collectors with chelation, the price is higher. Moreover, some oxidized ore collectors are not able to effectively capture the area of ​​the sulfide ore because of its too hard. Therefore, the combination of collectors can be used to achieve a better harvesting effect.

The agent has been applied in many copper oxide mines in many mines at home and abroad.

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