SU50202A1 - Method for processing of trap concentrate for isolating nepheline with simultaneous enrichment with rare earths - Google Patents

Description

The complexity of the complex of rocks that make up the Lovchorritic ore, as well as the chemical composition of the Lovchorrig itself, make it difficult to process it, necessitating its preliminary enrichment.

The enrichment method developed by the central testing station in Khibinogorsk (wet enrichment on the Bethle tables with subsequent magnetic separation) makes it possible to obtain Lovchorrite concentrates with a content not exceeding 4% of rare earths; higher enrichment is accompanied by large losses.

The method developed in the central chemical laboratory in Khibinogorsk, based on the selective solubility of minerals, makes it possible to decompose Lovchorrite, made minerals that are insoluble in acids (egirin, titanium-magnetite, sphene, etc.) in undecomposed form and produce high-grade rare earth concentrates. These methods resolved the issue of the possibility of obtaining rare-earth fluorides from Lovchorrite concentrates with a rare-earth content of not only 4%, but even 2.7%.

Along with the developed method, which allows to obtain rare fluorides

lands without the use of oxalic acid, there is a method developed by I. Zaozersky and Protserov. When testing this method, it was found that the Lovchorrite concentrate (enriched according to the Bethle method) obtained by the experimental plant D (in Moscow) is not standard, because the content of rare earths with it varies from 2.7 to 4%, and the aluminum content exceeds many times the content of rare earths. These two factors — the low content of rare earths and the presence of high aluminum contents — caused great difficulties in obtaining hydrates suitable for obtaining fluorides, according to the method of I. Zaozersky; The percentage of rare earths turned out to be insignificant.

Apparently, the Lovchorrite concentrate, which is currently produced by the plant, is not obtained from aegirino-feldspar veins containing Lovchorrit, but from nepheline-feldspar veins containing Lovchorrite.

You also dreamed that a large amount of nepheline, rapidly dissolving in acids, was present in Lovchorrite, the practical norm of sulfuric acid, designed mainly for decomposition of Lovchorrite, should be increased, the same as when processing decomposed mass with alkaline alkali (the amount of the latter should also be increased ).

Based on the above data and a whole series of experiments, the proposed method was developed, which makes it possible to decompose nepheline when treating trap concentrate with sulfuric acid, leaving the main mass of trap decomposing, decomposition to be carried out without the need for heat energy from the outside and without complicated - equipment with coating consumption for reagents is entirely due to extraction of aluminum, and concentrates or ore with any content of nepheline can be used for enrichment.

The essence of the method is as follows. Lovorritic concentrate is kneaded in the cold with the amount of concentrated sulfuric acid required to decompose nepheline (almost 2 cm HaSOi per unit weight of 1.84 is taken per 1 g of RlaOa, and to a uniformly wet mass, water is added dropwise until the mixture is wet). temperatures up to 90-95 °, after which the latter itself rises to 110 ° and then gradually decreases. After cooling, the decomposed mass, which is completely dry to the touch, is treated with an aqueous solution of caustic alkali until the aluminum hydrate formed by neutralization with alkali dissolves into sodium or potassium aluminate, depending on which alkali has been treated. Upon cooling, to the mass (the temperature of which from treatment with alkali rises to 50-60 °) add 10 times the amount of water relative to the weight of the taken Lovchorrite, stir well and allow to stand. After 20–30 minutes, the solution containing the main mass of aluminum and other salts of decomposition products of nepheline is decanted (if desired, a more complete extraction of aluminum in the form of aluminate, the second washing is performed with a 3% alkali solution). After decantation, some water is added to the precipitate, stirred and the liquid phase, which contains another decomposition product of nepheline-silicic acid, is separated from the solid phase, consisting of undecomposed Lovchorrite and its accompanying minerals (apatite, aegirine, titanomagnetite, etc., by otmuchivanie. ).

The obtained Lovchorritic concentrate, the weight of which in relation to the initial product is reduced directly in proportion to the weight of isolated nepheline, is correspondingly enriched in rare earths, the loss of which in the course of work does not exceed 3-5%.

The subject matter of the invention.

A method of processing trap concentrate for isolating nepheline while enriching it with rare earths by decomposing the concentrate with sulfuric acid followed by processing the decomposition product with a solution of caustic alkali and separating the aluminates and silica from the decomposed mass, characterized in that after the sulfuric acid is introduced into the mixture, the input t drops of water or thin streams in order to obtain an elevated temperature required for the cutting process.