SU71682A1 - Method of mineral depression during flotation - Google Patents

Description

Published 30 In modern flotation practice, two methods of mineral depression are used: I. Reagent-depressor interacts with a depressive mineral, forming a film on its surface that prevents exposure to this mineral of the reagent-collector. A typical example of such a depression can be depression of galena chromate or potassium bichromate when used as a xanthate collector. As a result of chromate exposure on the surface of galena, PbCgO4 lead chromate film is formed, and the solubility product is. This compound is below the solubility of both galena itself and lead xanthate. Therefore, under the action of chromate, galenite is coated with a chromate film, which excludes the possibility of exposing galenite to xanthate. II.The reagent-depressor, which does not form directly on the surface of the depressed mineral film, interacts with the reservoir: decomposes it, precipitates it or otherwise influences the reservoir, preventing it from affecting the mineral. IU "1E49 years I in most cases of depression is carried out according to the first method, which has a number of drawbacks: 1. Significant difficulty. A depressor for minerals that have a low solubility product, for example, such as barite (when used for flotation as an oleic acid collector or sodium oleate). In this case, it is necessary to select such a reagent as a depressant the solubility product and the solubility product of barite and barium oleate (if used as an oleate collector). Meanwhile, the solubility product of the barite itself is negligible (1X10 and the solubility product of barium oleate is even lower. An effective depressant for barite for these reasons has not yet been found. 2. The film forming on this depressed mineral is difficult to remove chemically. This creates significant difficulties when restoring the floatability of a depressive mineral (for example, flotation .. capacity of galena, depressed with chrompeak and covered with film

lead chromate cannot be recovered due to the extremely low solubility of lead chromate).

3. For the formation of a film on the surface of a depressed mineral, prolonged contact with the depressor (15-20 minutes) and its considerable consumption, measured in kilograms per ton of ore, is usually required. The proposed method does not have these disadvantages.

In contrast to the known methods of depression, this method does not form any films on the surface of the depressed minerals, and there is also no impact on the collector reagent (sedimentation or decomposition of the collector).

In the proposed method of depression, the depressant reagent does not affect the reservoir, but rather depresses by reducing the water solubility of the depressed mineral, which leads to a decrease in the rate of chemical reaction to the reservoir and mineral to such limits to the extent that flotation practically becomes impossible. A decrease in the solubility of the mineral is achieved by introducing an electrolyte into the pulp, which contains a ditched anion, in the case of using an anionic collector, or a cation, in the case of using a cationic collector, of the same name as the aniop or cation of depressed minerals.

The essence of the proposed method is as follows.

When using an anionic collector (as it happens in most cases) the reaction product between the collector and the mineral is the hardly soluble compound of the cation of the mineral with the anion of the collector. The mineral anion and the collector cation remain in solution. Since the reaction occurs in the ionic form (especially in the first stage, when the collector film has not yet formed on the surface of the mineral), it can be expressed by the scheme:

 An ,, - f Katr, „+ An ,,,,

reagent

En „.,

H-kat

ar, ", An,".

reagent 16

Here, “Kat and“ An, respectively, denote the cation and anion, and the indices “min and“ reagent — mineral and reagent. A chemical compound formed by the cation of the mineral with the anion of the reagent and causing the flotation of the mineral is circled in the frame.

The reaction equation shows that its rate with a constant amount of the reactant-collector depends on the concentration in the pulp of the ion Cat j j, j, (or, as each mineral molecule passes into the solution, both Cat min and An “Nn)

Since the product of the concentrations of the ions of the compound that goes into solution is a constant value, for the present case: I Anm "J ivd-i.,. H. 1 const, with square brackets indicating the concentration of the corresponding ion. As the concentration of the pulp increases, for example, the anion of the mineral, the concentration of the cation of the mineral decreases. It is easiest to do this by adding a reagent into the slurry, which contains the same anion as the mineral.

With an anionic reservoir, minerals can be depressed by injecting reagents into the pulp, which contain the same anion as is a part of the depressed mineral. The introduction of reagents with the same cation, of course, would lead to depression due to precipitation of the reservoir, but obviously, not only depressed mineral having a cation identical to the cation of the reagent to be added would become depressed, but also a mineral that should float .

The smaller the solubility product of a mineral, the more depressant its effect will be at the same amount of a depressant introduced into the pulp.

The depressions of the proposed method were established, in particular, on barite, celestine, galena and other minerals having a sulfate group as anion on the surface. For these minerals, sulfuric acid, sodium sulfate and potassium sulfate turned out to be effective depressants, since they all contain a sulfate group available in depressed miner als. The subject matter of the invention 1. Method of depression of minerals and flotation, characterized by - 3 - 71682 in that they reduce soluble; depressable minerals in water, 2. Acceptance of the method of claim 1, characterized in that to reduce the solubility of the depressed minerals in the pulp The electrolyte containing anion, in the case of using an anionic collector, or a cation, in the case of using a cationic collector, is the same as the anion or cation of depressed minerals.