INDUSTRIAL IMPLEMENTATION OF METHODS DEVELOPED FOR EXTRACTING GOLD FROM THE WASTE OF HYDROMETALLURGICAL PLANTS

ABSTRACT

The article discusses the development of methods for extracting gold from waste from hydrometallurgical enterprises. Experimental-industrial research were carried out on the content of non-ferrous metals in areas of the tailings dump, as well as the patterns of distribution of non-ferrous metals along the depths of the tailings, volume-phase distributions of non-ferrous metals in the tailings. The results obtained showed that generally high non-ferrous metals content (more than 0.8 g/t) was noted in average samples taken from a depth of 1-3 m, which occupied more than 40% of the surveyed area of the entire tailings dump. A high content of non-ferrous metals (more than 0.8 g/t) was noted in more than 50% of the surveyed area in the northern part of the tailings dump (depth 3 m); in the northeastern part of the tailings dump (depth 1-3 m), in the western part of the tailings dump (depth 5-6 m).

АННОТАЦИЯ

В статье рассматривается разработка методов извлечения золота из отходов гидрометаллургических предприятий. Были проведены опытно-промышленные исследование по содержание цветных металлов по участкам хвостохранилище а также закономерности распределения цветных металлов по глубинам залегания хвостов, объёмно-фазовые распределения цветных металлов в хвостохранилище. Полученные результаты показали что, в основном высокое содержание цветных металлов (более 0,8 г/т) отмечено по усреднённым пробам, отобранным из глубины 1-3 м, что занимало более 40% обследованного участка всего хвостохранилища. Высокое содержание цветных металлов (более 0,8 г/т) отмечено на более чем 50% обследованного участка в северной части хвостохранилища (глубина 3м); в северо-восточной части хвостохранилища (глубина 1-3 м), на западной части хвостохранилища (глубина 5-6м).

Keywords: tailings dump, extraction, processing, HMP-3, raw materials, non-ferrous metals.

Ключевые слова: хвостохранилищи, извлечения, переработка, ГМЗ-3, сырьё, цветные металлы.

Introduction

The amount of man-made waste for the purpose of processing mineral raw materials is increasing sharply. for the purpose of extracting the metals contained in them, and due to the high costs of extracting the metals contained in the primary ore, the extraction of metals from the waste is of great importance. Taking these into account, in order to extract metals from the waste, samples were taken from different points of the tailings dump, and the mineralogical composition, quantity, and volume location of the non-ferrous metals in them were studied. The waste dump of 3-hydrometallurgical plant was selected as the object of the research. Was invited to develop as a result of the conducted research.

Research methodology

Investigating the spatial and volumetric distribution of non-ferrous metals in tailings dump. The HMP-3 (Hydrometallurgical plant) tailings dump is a specially built facility with a total area of 800 hectares. Visual inspection and careful observation of the condition of the HMP-3 tailings dump shows that the relatively dry surface is 188 hectares constitutes. Among them:

• the north-western part is 25 hectares
• the northern part is 70.0 hectares
• the north-eastern part is 5.0 hectares
• the western part is 60 hectares
• the southern part is 28 hectares

The sample was selected from an area of 140.1 hectares, which is 75% of the total dry area of the tailings dump.

Classification according to the frequency (frequency) of occurrence of non-ferrous metals in the tailings dump. The frequency (frequency) of occurrence of the class of non-ferrous metals according to the conventional measurement value of non-ferrous metals production utility was determined.

According to the amount of non-ferrous metals and other technical and economic parameters of the technology, the degree of extraction of non-ferrous metals is at least 60%, the measured value of non-ferrous metals can be conditionally divided into three groups: low-useful (≤0.4 g/t), medium useful quantity (0.5÷0.7 g/t), high useful quantity (≥0.8 g/t).

The analysis of the frequency of meeting non-ferrous metals of different classes in the tailings dump and its spatial-volume distribution shows that their distribution is not very uniform:

I. North-west side of the tailings dump. Sampling conditions: a discrete plot to be analyzed is 0.1 hectares (square 33.3x33.3m). The selection depth is 1-3 meters. A total of 289 samples were taken from a depth of 1-3 meters (132 samples from the north side and the west side).

An area of 8 along the northern side of the tailings dump was inspected. 157 samples were selected, including 72, 72, 14 samples from the depth of 1, 2, 3 m, respectively. At a depth of 1-2 m, mainly 10% of the amount of selected samples and at a depth of 3 m - 50% of the amount of selected samples, has an amount of more than 0.8 g/t. The total share of the volume of non-ferrous metals distribution in the examined space is more than 0.8 g/t, mainly 15%.

On the western side, 8.4 hectares were examined, 132 samples were taken, including 127 samples from 1-2 m depth and 5 samples from 3 m. At a depth of 1-2 m, mainly in 25% of the area, the amount of non-ferrous metals is more than 0.8 g/t. At a depth of 3 m, the share of samples with an amount of 0.8 g/t is 20% of the total selected samples. The total share of the distribution volume of non-ferrous metals exceeding 0.8 g/t is 27%.

II. North side of the tailings dump. Sampling conditions: a discrete plot to be analyzed is 0.25 hectares (square 50x50m). The selection depth is 1-3 m. A total of 333 samples were selected from 232 sampling points (58 hectares).

On average, 90% of the sampled volume of raw material has a non-ferrous metals content of more than 0.5 g/t, and 55% of the sample has a non-ferrous metals content of more than 0.8 g/t.

III. The north (northeast) side of the tailings dump. Sampling conditions: a discrete plot to be analyzed is 0.10 hectares (square 33.3x33.3m). The selection depth is 1-3 m. A total of 46 samples were selected from 39 sampling points (4.3 hectares). On average, the non-ferrous metals content of 90% of the entire tested volume of raw material is more than 0.8 g/t.

IV. West side of the tailings dump. Sampling conditions: a discrete plot to be analyzed is 0.10 hectares (square 33.3x33.3m). The selection depth is 1-3 m. A total of 482 samples were selected from 226 sampling points (25 hectares). On average, 90% of the sampled volume of raw material has a non-ferrous metals content of more than 0.5 g/t and 45% of the area has a non-ferrous metals content of more than 0.8 g/t.

V. South side of the tailings dump. Sampling conditions: a discrete plot to be analyzed is 0.10 hectares (square 33.3x33.3m). The selection depth is 1-3 m. A total of 153 samples were selected from 74 sampling points (8.0 hectares). On average, over 90% of the tested volume of raw material has a non-ferrous metals content of more than 0.5 g/t and 40% of the area has a non-ferrous metals content of more than 0.8 g/t.

VI. The southern (southeast) side of the tailings dump. Sampling conditions: a discrete plot to be analyzed is 0.10 hectares (square 33.3x33.3m). The selection depth is 1-3 m. A total of 259 samples were selected from 126 sampling points (14.0 hectares). On average, over 90% of the tested volume of raw material has a non-ferrous metals content of more than 0.5 g/t and 40% of the area has a non-ferrous metals content of more than 0.8 g/t.

Based on the research on the occurrence frequency of non-ferrous metals in the amount of 0.8 g/t in the tailings dump, compared to the HMP-1, HMP-2 and HMP-4 tailings dumps, it is possible to enter the HMP-3 tailings dump into man-made raw materials.

A probe method of analysis is used to perform the average acceptable assay and the non-ferrous metals cyanidation test.

Spatial-volume distribution of non-ferrous metals in the tailings dump.

To visually demonstrate the distribution of non-ferrous metals by quantitative classes, 4 gradations of non-ferrous metals concentration were selected (g/t): 0.4-0.8; 0.8-1.2; 1.2-1.6; 1.6-2.0.

Non-ferrous metals in the dump is very different along its sides. Localization of high amount of non-ferrous metals (0.8-1.6 g/t) is observed in separate sections of the tailings dump. This is especially visible in the west, south-west and north-east part of the tailings dump at a depth of 1-3 m.

A detailed study of the non-ferrous metals concentration in the dump shows that there is a similarity in the localization of high non-ferrous metals content in terms of depth of placement in the northwestern and northern parts of the dump. An anomalous amount of non-ferrous metals in the range of 1.6-2.0 g/t was detected along the edges in the northeastern and southeastern parts of the dump.

In the western part of the tailings dump, at a depth of 1-2 m, there is a similarity in the distribution of non-ferrous metals by concentration classes.

A high non-ferrous metals content (more than 0.8 g/t) according to averaged samples taken from a depth of 1-3 m is observed mainly in more than 40% of the examined section of the entire tailings dump.

A high amount of non-ferrous metals (more than 0.8g/t) is observed in more than 50% of the examined section: in the northern part of the tailings dump (3m deep); in the northeastern part of the dump (depth 1-3 m), in the western part of the dump (depth 5-6 m).

Studying the laws of distribution of non-ferrous metals according to the depth of waste location. In order to determine the pattern of non-ferrous metals concentration according to the depth of the waste location, a discrete sampling of 0.5 m each was carried out at two points in the northern part of the dump. The results of the study are given in figure 1.

In the northern part of the tailings dump, there is no visible accumulation of non-ferrous metals concentration at the depth of location of metallurgical waste (1-3m). Therefore, in order to increase the static data, 2 more points from the southern part of the tailings dump and 4 points from the western part of the tailings dump were selected. Sampling depth is 6 m, sample sampling is 1 m. 36 samples were selected from 6 sampling points. The results of the study are presented in figures 2 and 3.

Deep sampling data from the southern part of the dump shows consistent non-ferrous metals grades in the 0.7-0.8 g/t range.

Depth sampling data from the western part of the dump indicated non-ferrous metals, mostly concentrated, at depths of 3-5 m and in the 0.8-1.2 g/t range.

In the dump of the Marjonbulok Non-ferrous metals Extraction Plant (MGEP) of the Northern Mining Department, there are no visible patterns of increase in non-ferrous metals concentration depending on the depth of the waste location. The relatively large area of ​​the dump (840 hectares) and the low thickness of the waste location (6-7 m) may be the reason for this, which does not observe non-ferrous metals accumulation in a vertical-dynamic order. At MGEP, the thickness of the waste deposit is 25-30 m, and therefore, the accumulation of cyanidated non-ferrous metals is observed in the lower part of the dump.

Figure 1. Variation of non-ferrous metals concentration with depth

Figure 2. Distribution of non-ferrous metals by sampling depth in the southern part of the tailings dump (samples № A-900; V-901) and western part (sample C-935)

Figure 3. Non-ferrous metals distribution by sampling depth in the western part of the dump ( A-sample 990; B- sample 1016; C- sample 1033)

Results and discussion

Determining the economic efficiency of the developed methods of processing non-ferrous metals-containing man-made raw materials. Assessment of the economic feasibility of man-made raw materials processing. The usefulness of extracting non-ferrous metals from man-made raw materials (Fig. 4-6) mainly depends on the concentration of non-ferrous metals in the man-made raw materials and the degree of oxidation (the size (quantity) of the cyanidable form of non-ferrous metals).

Figure 4. Dependence of non-ferrous metals extraction from man-made raw materials on the degree of oxidation of raw materials

Figure 5. The dependence of non-ferrous metals extraction utility on the amount of non-ferrous metals in man-made raw materials (when the price of non-ferrous metals is $34)

Figure 6. The dependence of non-ferrous metals extraction utility on the amount of non-ferrous metals in man-made raw materials (when the price of non-ferrous metals is $40)

Conclusions

Taking into account the average non-ferrous metals content of 0.8 g/t (50 percent), at the world market non-ferrous metals price of $40, it is useful to extract at least 50% of the non-ferrous metals from the tailings dump by the direct cyanide method. Therefore, when choosing extraction methods, it is necessary to take into account the possibility of increasing the cyanidable form of non-ferrous metals. Positive success can be expected in the biological destruction of rocks directly in the tailings dump.

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