Studies on heap leaching of gold with the addition of sodium acetate as an intensifying reagent

One of the cheapest methods of extracting gold is heap leaching. However, the recovery of gold by this method is relatively low, compared with cyanidation of the crushed material, so the search for the ways to intensify leaching and increase gold recovery is an urgent task. Investigations on heap leaching of gold from the gold-bearing ore of the Sari Gunay deposit were conducted using a promising reagent sodium acetate to intensify the heap leaching process. The results of assay-gravimetric, chemical, mineralogical and granulometric analyses of oxidized ore are presented. The average gold content in the ore was 2.90 g/t. According to the electron probe analysis, gold in the ore is present in the form of fine (micron) inclusions in minerals and ore rocks. Comparative studies on heap leaching of gold from the crushed ore with a grain size of –20 + 0 mm with the addition of sodium acetate and without that were carried out. The degree of gold recovery with sodium acetate at a flow rate of 0.5 kg/t was 58.74%, that without sodium acetate was 54.69%, i.e. the addition of the reagent provides an increase in recovery of more than 4%. Leaching with the addition of the reagent also reduces sodium cyanide consumption from 0.65 to 0.59 kg/t. The research results have shown that sodium acetate can be used to intensify the process of heap leaching of gold when the ore size is –20+0 mm.

Hyperspectral Characteristics of Oil Sand, Part 1: Prediction of Processability and Froth Quality from Measurements of Ore

This study is the first of two companion papers using hyperspectral data to generate predictive models of oil sand ore and froth characteristics as a potential new means for process control. In Alberta, Canada, shallow oil sands deposits are accessed by surface mining and crushed ore is transported to a processing plant for extraction of bitumen using flotation processes. The ore displays considerable variability in clay, bitumen, and fines which affects their behavior in flotation units. Using oil sand ore spanning a range of bitumen and fines characteristics, flotation experiments were performed to generate froth in a batch extractor to determine ore processability (e.g., separation performance) and froth characteristics (color, bitumen, solids). From hyperspectral observations of ore, models can predict the %bitumen content and %fines (particle passing at 44 and 3.9 µm) of ore but the models with highest r2 (>0.96) predict the solids/bitumen of froth and the processability of ore. Spectral observations collected on ore upstream of the separation vessels could therefore offer a first order assessment of froth quality for an ore blend before the ore enters the plant. These models could also potentially be used to monitor and control the performance of the blending process as another means to control the performance of the flotation process.

Study of the process of cyanide leaching of gold using sodium acetate at different ore sizes

Intensification of metal extraction by leaching is a complex of organizational and technical measures aimed at achieving the fastest and complete extraction of metal from ore. Measures to intensify leaching are aimed at completely or partially neutralizing the causes that cause a decrease in the leaching rate. Tests were performed on cyanide leaching of gold from gold-containing ore with the addition of sodium acetate to intensify the leaching process. The results of assay-gravimetric, chemical, mineralogical and granulometric analysis of oxidized ore are presented. According to electron-probe analysis, gold in the ore is present in the form of thin (micron) inclusions in minerals and ore rocks. A study was conducted on leaching of crushed ore with a size of 90% of the class -0.074 mm and crushed ore with a size of -12+0 mm. Leaching of crushed ore with a size of 90% of the class -0.074 mm showed that when adding sodium acetate, the gold recovery rate increases by 1.13 % compared to leaching without adding this reagent. When leaching crushed ore with a size of -12 + 0 mm with the addition of acetate, gold recovery increases by an average of 4 %, and the kinetics of gold dissolution improves. Research data prove that sodium acetate can be used to intensify gold at a ore size of -12+0 mm and in larger ore classes for leaching gold.

Ore image segmentation method using U-Net and Res_Unet convolutional networks

Image segmentation has been increasingly used to identify the particle size of crushed ore. How to accurately identify the ore particles in complex a environment is particularly important.

INVESTIGATION AND OPTIMIZATION OF A CLOSED CIRCUIT CRUSHING OF COPPERMOLYBDENUM ORE

To control the processes of ore treatment proposed adapted to the conditions of a closed cycle crushing-screening criterion "output productive class -2 + 10 mm", reflecting the effectiveness of all processes. The dependence of the outputs of the individual classes of ore and the proposed optimization criterion parameters of the grinding process shows their relationship with the energy intensity of the process. It is shown that the increase in the load on the screen causes a decrease in the screening efficiency and an increase in the mass fraction of class +2 mm in the circulating ore. Excessive increase in the width of the discharge gap of the crusher causes an increase in the output of the circulating product and an increase in energy consumption. Reducing the discharge gap of less than 7.5 mm leads to an increase in the output of the class - 2 mm. An improved system and algorithm for optical analysis of ore size was proposed and tested. The sensors for controlling the granulometric composition of ore are located above the conveyors for the transportation of over-and under-mortar products of the screening operation. The optical analysis mode provides for the sequential switching on / off of feeding conveyors and crushers, thereby ensuring the flow of the crushed product into the measurement zone from one crusher. The total duration of the analysis of ore from 6 crushers is 12 minutes, which does not affect the final performance of the device of crushing. The application of the developed algorithm can significantly improve the accuracy of the analysis of the size of crushed ore and reduce the power consumption during the processing of ore.