RU2616698C1 - Recovery method of ultradispersed diamonds from impactites - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: recovery method of ultradispersed diamonds from impactites includes prelimenary preparation of material by crushing and grinding to produce a particle size less than 0.25 mm. The crushed material is subjected to gravitational enrichment at the concentration table to obtain the concentrate and tailings, at that the tails are directed to the dump, and the concentrate is subjected to ultrasonic treatment at a frequency from 22 up to 44 kHz for 15 to 30 minutes. The toluene in the amount of 10 to 40% from volume is added to the crushed material , and subjected to ultrasonic leaching at frequency from 22 kHz to 44 for 15 to 30 minutes, then subjected to filtration and washing with water.

EFFECT: extraction of diamonds nano- and microfractions of impact origin raw materials, environmental safety of the diamond raw material processing increase.

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Description

The invention relates to the field of mineral processing, in particular to the extraction of ultrafine diamonds from raw materials of impact origin, and can be used in the processing of kimberlite ores.

A known method for the extraction of diamonds from ores (patent RU No. 2320420, publ. March 27, 2008), which includes crushing the ore in a closed cycle with screening, fractionation of crushed ore by size into oversize and sublattice products, the extraction of diamonds from oversize coarse-grained ore fractions by X-ray fluorescence separation, tailing to tailing.

The disadvantages of this method is the low extraction of diamond crystals with a particle size of less than 0.5 mm

A known method of cleaning synthetic ultrafine diamonds (patent RU No. 2168462 publ. 06/10/2001), including thermal oxidation in air at 380-440 ° C. Thermal oxidation of the diamond charge is carried out at a speed of 2.5-10.0 deg./min with subsequent isothermal exposure for 2-4 hours

The disadvantage is the lack of the necessary completeness and sequence of operations to increase the extraction of diamonds of the entire size range (micro and nanoscale), as well as the high energy consumption when heated to a temperature of 440 ° C on an industrial scale.

A known method for the extraction of diamonds from diamond-containing raw materials (patent RU No. 2201298, publ. 03/27/2003), which includes grinding the original diamond-containing raw materials, classification of crushed raw materials by size classes, initial enrichment of classified raw materials, grinding industrial products obtained after enrichment of classified raw materials, subsequent enrichment, grinding and refinement of industrial products, while these operations are carried out with dry raw materials at negative or positive temperatures. The pulverulent fraction is separated into the industrial product to obtain diamond powder on electrostatic precipitators equipped with electric separation elements.

The disadvantages of the method are the bulkiness of the equipment, the energy intensity of the processes, as well as the complex layout of the production line for its implementation.

A known method of separation of ultrafine diamonds from stable aqueous suspensions (copyright certificate SU No. 1614354, publ. 10.01.1996), which includes the coagulation of diamond with its subsequent deposition. Coagulation of diamond from a suspension is carried out by treating it with an electric field at a tension of 2-50 kV / m in the interelectrode space isolated from the electrodes by fluoroplastic membranes.

The disadvantage is the increased energy consumption due to the use of an electric field. Also a disadvantage is the speed of the proposed method, due to the small particle size, very low processing speed of the suspension.

A known method of extracting diamonds from diamond-containing raw materials (patent application RU No. 94027741, publ. 06/27/1996), adopted as a prototype, including high-temperature alkaline treatment, water leaching of the product, filtering and washing with water, acid treatment of alkaline cake, before alkaline processing, the raw material is fired with the addition of a dry salt of potassium chloride at 450-660 ° C for 3-6 hours, and alkaline treatment of the cinder obtained is carried out using dry alkali taken in the ratio (1-1.5): 1 to the mass of cinder at 480 -520 ° C 30-60 m in. The acid treatment of alkaline cake is carried out with sulfuric acid at a flow rate of 1.0-1.2 l / kg cake.

The disadvantages are the need for the process at high temperatures, as well as increased consumption of reagents, which negatively affects the environment.

The technical result of the invention is the extraction of nano- and microfractions of diamonds from raw materials of impact origin, as well as improving the environmental safety of processing diamond-containing raw materials.

The technical result is achieved in that the preliminary preparation of the material is carried out by crushing and grinding to obtain a particle size of less than 0.25 mm, the crushed material is subjected to gravitational enrichment on a concentration table to obtain concentrate and tailings, while the tailings are sent to the dump, and the concentrate is subjected to ultrasonic treatment frequency from 22 to 44 kHz for 15 to 30 minutes, toluene is added to the crushed material in an amount of 10 to 40% by volume and is subjected to ultrasonic leaching vaniyu at a frequency of 22 to 44 kHz for 15 to 30 minutes, then subjected to filtration and washing with water to obtain solid phase microfractions diamond and diamond nanofraction liquid phase.

The method of extraction of ultrafine diamonds from impactites is illustrated by the following figures:

FIG. 1 is a flow chart of the extraction of diamonds from impactites.

FIG. 2 - micrographs of diamond crystals.

The implementation of the method is as follows (Fig. 1). The crushing of the source material with a particle size of 0-10 mm is carried out in a jaw crusher, then the crushing product with a particle size of 0-2 mm is fed to a ball mill for grinding to obtain a particle size of less than 0.25 mm. Ball mill loading is 45% of the mill volume. The crushed material is subjected to gravitational enrichment on a concentration table to obtain two products (concentrate and tails). The resulting concentrate for more complete disintegration and destruction of agglomerates is subjected to ultrasonic treatment with a frequency in the range of 22-44 kHz for 15-30 minutes. To intensify the process of disintegration, ultrasonic treatment is carried out in an aqueous medium. Further, the selection of crystals of ultrafine diamonds is carried out by leaching. Toluene is added to the material in an amount of 10-40% by volume. Ultrasonic leaching is carried out at a frequency of 22-44 kHz for 15-30 minutes, after which the material is filtered and washed with water. The resulting solid phase contains microfractions, and the liquid fraction contains nanofractions of ultrafine diamonds. Gravity dressing tailings are sent to the dump.

Example 1. The initial concentration of ultrafine diamonds 5-30 carats per 1 ton of tagamites. Estimated reserves - 300 ml carats.

The estimated structure of impact diamond — a highly flattened polycrystal (length – thickness ratio 10–50) with nanoscale grain (nanodiamond size up to 10 nm) (Fig. 2), preserves the genetic form of graphite inclusions in the target material: for the Kara impact — shales and carbon rocks , possibly part of the carbon black shales, partly coal and marine carbon bio-carbon.

ZUVIT - debris rocks (breccias) of impact (impact-meteorite) origin, which are allogeneic breccias.

TAGAMIT - a massive glassy rock of impact origin, having an allochthonous occurrence.

Tagamite and zuvite from the Kara Astrobleme are averaged and crushed in a jaw crusher, then crushed in a ball mill to a particle size of 80% - 0.25 + 0 mm. The crushed material is separated on a concentration table to obtain two products (concentrate and tails). Water is added to the concentrate. The resulting material is disintegrated in an ultrasonic bath with a frequency of 22-44 kHz for 15-30 minutes. Toluene is added to the material. The ratio of water to toluene is 80:20. Ultrasonic leaching is carried out at a frequency of 22-44 kHz for 15-30 minutes, after which the material is filtered and washed with water. The resulting solid phase contains microfractions, and the liquid fraction contains nanofractions of ultrafine diamonds.

Nanodiamonds are contained in zuvite, there are no nanodiamonds in tagamite, only microdiamonds - at the time of the formation of tagamite, nanofractions burn out. Based on the totality of these differences, we can conclude that the time of ultrasonic treatment affects the extraction of diamond nanofractions.

The developed method allows to increase the efficiency of extraction of nano- and microfractions of diamonds from raw materials of impact origin.

Claims (1)

A method of extracting ultrafine diamonds from impactites, including leaching, filtering and washing with water, characterized in that the preliminary preparation of the material is carried out by crushing and grinding to obtain fineness of less than 0.25 mm, the crushed material is subjected to gravity enrichment on a concentration table to obtain concentrate and tailings, in this case, the tails are sent to the dump, and the concentrate is subjected to ultrasound treatment with a frequency of 22 to 44 kHz for 15 to 30 minutes, to the crushed mat ialu toluene was added in an amount of from 10 to 40% by volume, and subjected to ultrasonic leaching at a frequency of 22 to 44 kHz for 15 to 30 minutes, then subjected to filtration and washing with water to obtain solid phase microfractions diamond and diamond nanofraction liquid phase.

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