RU2526959C1 - Method of determining gold mineralisation of rock formation - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: method of determining gold mineralisation of rock formation comprises multistage crushing of raw material to fractions of the size not greater than 0.5 mm, the subsequent classification of the resulting material and its processing with bromoform. Classification is carried out by sedimentation with the separation of the material class of -0.05+0.02 mm of water discharges, followed by drying and sieving the remaining material with the separation of the fraction -0.5 +0.1 mm and -0.1+0.05 mm, treating each of the resulting classes with 10-30% alcohol solution of bromoform. Sedimentation is carried out once with the accumulation of sediment for 15-20 min and repeatedly for 3-5 minutes, followed by the integration of the water discharges obtained during it.

EFFECT: increase in reliability of determining of gold areas and determining areas of gold mineralisation.

2 cl, 1 ex

Description

The invention relates to the field of exploration when conducting prospecting for gold, as well as in the analysis of rocks, ores, products of their processing and can be used in geology, geochemistry to identify gold-bearing areas, determine the areas of gold-bearing and increase the efficiency of gold extraction from mining rocks.

It is known that the main losses in the mining of placer and ore gold are accounted for by thin, lamellar and pulverized gold with a particle size of from a millimeter to several microns.

According to modern estimates, with modern methods of gold mining using traditional washing methods, from 20 to 50% of gold is lost. Stricter environmental requirements, such as a ban on mercury, also limit the possibilities for reducing losses. Another, no less important, side of the “thin gold” problem is that it is time to pay attention to a significant amount of man-made placers accumulated over many decades containing a significant amount of fine fine gold.

Thus, the relevance of the search for effective technical means and methods for identifying gold-bearing areas, determining the areas of gold-bearing and for extracting such gold from the feedstock and its processing products is obvious.

A known method of dry preparation of geological or technological samples of gold-bearing ores and placers for analysis in order to reduce the cost of the extraction process and increase the reliability of determining the gold content of rocks. A dry sample containing large gold is crushed and sent to a special classifier, made in the form of a vertical pipe with an upward air flow. The obtained light fraction of the dry sample is sent for precipitation to sequentially installed centrifugal apparatuses, and the obtained heavy fraction - a gold-containing concentrate - is crushed and sent for processing similar to the processing of the initial sample. After that, the final gold-containing concentrate is completely, and the light fraction - after mixing and reduction, is sent for analysis.

The disadvantage of this method is its complexity, the need for special equipment - classifiers, moreover, it does not provide the extraction of fine fine grains of a useful component [RF patent No. 2372152, G01N 1/00, publ. November 10, 2009].

A known method for determining the gold content of rocks during prospecting for gold, including sampling, grinding, mixing with non-melting solid royal vodka and heating the mixture for 3-5 minutes, in a closed crucible until sublimation is obtained in the form of a coating on the walls of the crucible. As a result, the presence of gold in the sample is judged visually by the yellow and / or orange color of the plaque [application for the grant of a patent of the Russian Federation No. 2007148258, G01N 1/00, publ. 06/27/2009].

However, this method does not ensure the reliability of the results and does not provide the extraction of fine fine grains of the useful component.

In recent years, new methods for studying rocks have become widespread, among which a special place is occupied by the method of heavy fractions or artificial concentrates, which makes it possible to study accessory minerals of igneous rocks.

A known scheme for the allocation of accessory minerals from basic and ultrabasic rocks, taken by us as a prototype, proposed by V. Lyakhovich [Methods of separation of accessory minerals. - M .: Nedra, 1981. - 86 p.].

The peculiarities of the chemical composition of accessory minerals are that they contain elements that are present in the rock in extremely small quantities, but they give a more complete and perfect idea of the studied rocks.

The technique involves crushing the source material to a fraction of no more than -0.5 mm by multi-stage crushing with sieving of the fine fraction after each crushing cycle, dusting and drying of the material, followed by electromagnetic separation into non-magnetic and magnetic fractions. Next, accessory and rock-forming minerals are isolated from the non-magnetic fraction, and the bromoform is divided into heavy and light fractions.

The light fraction is further refined, screening and sizing are carried out, they are subjected to electromagnetic cleaning and finishing to monomineral fractions.

The heavy fraction is subjected to division in heavy liquids to obtain mineral concentrates of different densities, electromagnetic purification and refinement to monomineral fractions are carried out.

The magnetic fraction is subjected to electromagnetic separation into low magnetic and medium magnetic fractions with the release of rock-forming minerals.

The obtained fractions are subjected to division in heavy liquids and sizing in bromoform.

Many works from the listed sequence can be repeatedly repeated in a different sequence.

The described method allows us to establish a diverse species composition of ore minerals, but it is very difficult to perform. Moreover, the technique is not intended to work with “thin” classes, ultrafine fractions of the order of -0.05 + 0.02 mm, which can contain both gold and other valuable elements from rocks.

The specified scheme is also outlined by V.V. Mikhailov, V.V. Gordienko. "The simplest laboratory methods for isolating monomineral fractions": Textbook. Method. allowance, St. Petersburg. state Univ., 2012, pp. 24-26.

The objective of the invention is to simplify the method of separation of accessory minerals from rocks and ensuring the allocation of ultrafine fractions of a useful component,

EFFECT: increased reliability of revealing gold-bearing areas and determining areas of gold-bearing

The problem is solved in that in the method for determining the gold content of rocks, including multi-stage crushing of the source material to a fraction of not more than -0.5 mm, the subsequent classification of the obtained material and processing it with bromoform, the classification is carried out by sedimentation with the separation of the material class -0, 05 + 0.02 mm from water drains, subsequent drying and sieving of the remaining material with the separation of fractions of -0.5 + 0.1 mm and -0.1 + 0.05 mm and processing of each of the obtained classes with 10-30% alcohol solution bromoform.

Sedimentation is carried out once with the accumulation of sediment for 15-20 minutes and repeatedly for 3-5 minutes, followed by combining the resulting water discharge.

Sedimentation is a method of separation by size (size) of clay fractions, taking into account the time of deposition of the material. The inclusion of this separation stage in the scheme increases the reliability of the content of the desired minerals (gold) due to the capture of ultrafine fractions. Ultrafine fractions are relevant now, because new instrumental methods (instrumental, methodological, etc.) provide the opportunity to study them.

It is known that when washing in bromoform, small grains of gold are not wetted and float away to workings. To avoid this, it is proposed that the class -0.05 and -0.1 + 0.05 be washed in rinse bromoform (alcohol + 10-30% bromoform), where superfine “gold grains” turn out to be.

Example

A sample of the studied material - sulfide ores weighing 200 g (the sample can be of any complexity in composition) is crushed to a fraction of not more than -0.5 mm by multi-stage crushing, then sedimentation is carried out

Pour the sample with distilled water so that the height of the water column corresponds to 20-25 cm, mix and stand for no more than 15-20 minutes. After 15-20 minutes, the larger class -0.05 mm is deposited, and the smaller one remains in suspension. The suspension is drained, particles of less than 0.02 remain in the obtained slurry, the suspension is defended, and the sediment is analyzed.

Then re-fill the sample with distilled water, mix and stand for no more than 3-5 minutes. The procedure is repeated many times until “clean water” (the repetition of the process depends on the quality of the starting material - the sample)

Water plums are combined, defended, the precipitate is separated and dried. The result is a material weighing about 2 grams of fine (ultrafine) -0.05 + 0.02 sediment.

After that, the remainder of the sample is dried and sifted, resulting in a class of -0.5 + 0.1 mm and -0.1 + 0.05 mm. After drying and dispersion, 60 and 130 grams, respectively, are obtained.

With further washing of each of the selected classes in an alcoholic solution of bromoform (alcohol + 10-30% bromoform) receive:

- in the class -0.5 + 0.1 - no gold was found

- in the class -0.1 + 0.05 - about 10 grains of gold

- in the class -, 0.05 + 0.02 - 10-11 grains of gold (obtained in the ultrafine required class)

The proposed method can be used in the analysis of any stone material. Samples may be more or less complex in terms of mineral composition, depending on the amount of minerals, their relationships (intergrowths), etc.

When using only one sieving, as well as without sedimentation, there is a loss of the ultrafine class, the most informative for predicting the gold content of areas.

As a result, the method allows to isolate ultrafine fractions of gold, which, undoubtedly, increases the reliability of revealing gold-bearing areas and determining the areas of gold-bearing. Moreover, the method is becoming cheaper.

The proposed method may be applicable in the field, in this case, the efficiency (focus) of the search operations is increased, because the area of the most promising sites is being specified on the spot.

Claims (2)

1. The method of determining the gold content of rocks, including multi-stage crushing of the source material to a fraction of not more than -0.5 mm, the subsequent classification of the obtained material and processing it with bromoform, characterized in that the classification is carried out by sedimentation with the separation of the material class -0.05 + 0 , 02 mm from water drains, subsequent drying and sieving of the remaining material with the separation of fractions of -0.5 + 0.1 mm and -0.1 + 0.05 mm and processing of each of the obtained classes with a 10-30% alcohol solution of bromoform. 2. The method according to claim 1, characterized in that the sedimentation is carried out once with the accumulation of sediment for 15-20 minutes and repeatedly for 3-5 minutes, followed by combining the resulting water discharges.