Исследование реагентного режима флотации одного из золоторудных месторождений Восточного Забайкалья

This research focuses on the hydrometallurgical processing of auriferous ores and their processing products, namely, flotation and gravity concentrates. The main valuable component of an ore sample of any deposit is gold. The gold content should be in the range of 11.11–12.87 g/ton. The main rock-forming minerals of the original ore are quartz (60.1%), quartz–chlorite–micaceous aggregates (3.8%), and carbonates (7.1%). In this study, original ores of various sizes were treated by direct and sorption cyanidation under various leaching modes, and the results obtained were presented. The original ore was leached with various concentrations of sodium cyanide (NaCN) in solution to study the effect of the complexing agent concentration on gold recovery. Data on the dynamics of leaching revealed that a decrease in the concentration of NaCN in solution from 0.2% to 0.03% leads to a decrease in gold recovery in solution by 26.81%. Original ores could easily be processed using hydrometallurgical methods. The recovery of gold with a coarseness of 95% − 0.045 mm from the original ore averaged 97.77%. This work features a full range of studies on the hydrometallurgical processing of concentrates and gravity tailings, as well as the effects of flotation concentration of gold recovery. The gravity concentrate is resistant to intensive cyanidation (i.e., only 67.07% gold recovery into the solution). The use of 1% lead nitrate (PbNO3) during intensive cyanidation could reduce the refractoriness of the concentrate and increase the recovery of gold into the solution by up to 94.35%. The total gold recovery from gravity concentrate is 98.71%, and the recovery of gold by cyanidation of gravity tailings with a cyanide concentration of 0.2% averages 96.57%. The recovery of gold during leaching of the flotation concentrate at the original size (95.5% − 0.074 mm) and a cyanide concentration of 0.2% is 96.64%. A decrease in the size of the flotation concentrate from 95.5% − 0.074 mm to 95% − 0.02 mm leads to a decrease in gold recovery by 35.43% because of the strong chemical activation of the material during grinding.

The article discusses the results of studying the material composition and the development of technology for processing gold-bearing sulfide ore samples. The material composition of the ore samples was studied by spectral, chemical, assay and rational analysis of gold and silver. Based on a study of the material composition of the ore samples, the following conclusions were made: gold and silver are the industry's most valuable components. It is shown that the use of sulfuric acid treatment of a cinder of graviofloraf concentrate can allow to improve the technological performance of the process. As a result of the mixture of gravio-flotation concentrate after sulfuric acid treatment drying, grinding to a size of 95% CL. -0,074+0 mm and subjected to sorption cyanidation. In the initial cake, the content of gold -77.83 u. e. and silver-16.3 u. e., the concentration of sodium cyanide 0.15%, the ratio W:t=2:1; resin AM-2B-5% of the pulp volume, the duration of cyanidation 36 hours.the Content in the tailings of cyanidation of gold - 6.5 u. e., and silver - 4.8 u. e. the Extraction of noble metals in solution and on the resin was 91.65 and 70.55%, respectively. Through extraction of 87.63% gold and 55.6% silver from ore.

The main sources of spectral interferences in atomic emission spectral analysis (AESA) are considered, including both wide-range (bremsstrahlung and recombination continuum, radiation of hot condensed particles and electrode ends, scattered light in the spectrometer, overlapping of the analytical line by the wings of the neighbor strong spectral lines of interfering elements, imposition of the components of molecular bands with the very close lines) and narrow-band (partial or complete overlapping of the analytical line with atomic or ionic lines of the sample elements, electrodes and discharge atmosphere; superposition of spectra from higher orders of reflection in conventional diffraction spectrometers and from neighboring orders in two-dimensional echelle spectrometers). The features of their manifestation in various sources of spectrum excitation (flames, DC arc, spark discharges, arc plasma discharges, inductively coupled plasma, microwave plasma, low-pressure electric discharges, laser spark) are considered. The possibilities of reducing the level of spectral interferences or elimination of the spectral noise at the stage of design and manufacturing of AESA devices, as well as upon selecting and adjusting of operation conditions of the analysis are shown. Much attention is paid to the most easily implemented in practice off-peak correction of wide-range spectral interferences. The modern methods of background correction under the spectral peak (under-peak) using a software for atomic emission spectrometers and providing creation of various mathematical models of the background signal in the vicinity of the analytical line at the stage of developing a specific AESA technique are considered. The issues of the choice of spectral lines for analytical measurements, tables and atlases of spectral lines, electronic databases used for this purpose are considered in detail. Specific features of application of the method of inter-element correction with direct spectral overlapping of the lines are given. The operating sequence for taking into account spectral interferences when developing the analysis techniques is proposed.

The PURPOSE of this study is the efficiency test of a domestic depressor reagent under flotation of carbonaceous gold-bearing ores of various deposits. METHODS. Quantitative X-ray fluorescence, phase, atomic absorption, gravimetric and ICP-AES analyzes are used to determine the chemical composition of the ore. The mass fraction of the organic form of carbon is measured by the LecoSC-144 DR determinator. Gold content is determined using the assay-gravimetric analysis. Flotation feed is prepared using the Knelson KC-MD3 centrifugal concentrator. The flotation studies are carried out using gravity tailings and flotation machines of a mechanical type. RESULTS AND THEIR DISCUSSION. The study results show that the use of carbon suppressant reagent in flotation concentration increases the flotation concentrate quality by the gold content, while preserving the recovery level of the valuable component. It also contributes to the reduction in the yield of the flotation concentrate by decreasing the mass fraction of organic carbon and rock-forming minerals of the ore. CONCLUSIONS. The conducted study has found out the domestic reagent to be an effective depressant of a carbonaceous substance under flotation concentration. This fact allows to talk about its prospective use under flotation of carbonaceous gold-bearing ores.

Introduction: The problem of bone trauma and restoration of bone integrity with defects of various localization, shape and size is particularly relevant today. Objective: To determine the features of post-traumatic dynamics of the mineral elements content in the bone tissue of the mandible using octacalciumphosphate. Materials and Methods: The study was conducted on 65 sexually mature male rabbits weighing 2.5-3.0 kg, aged 6-7 months which were divided into 3 groups (20 rabbits each): Group I - control - the bone tissue defect healed under a blood clot; Group II - the defect was filled with native octacalciumphosphate (OCP-N); Group III - the defect was filled with octacalciumphosphate with chitosan and ampicillin (OCP-N-Chitosan-Ampicillin). Five intact animals were used to study the normal mineral composition of the rabbit mandibular bone tissue (MBT). The content of five mineral elements was determined using atomic absorption and emission spectral analysis. Data was carried out after 7, 14, 21, 28, 35, 56, and 84 days. Results: It was established that the calcium and phosphorus content in the MBT were lower than in the control, but higher than normal. Magnesium and sodium levels with OCP-N were similar to controls, while with OCP-N-Chitosan-Ampicillin, they returned to normal. Sodium levels were higher than controls. Sodium levels were higher than the first control group data. Magnesium levels, while using OCP-N were higher than the parameters for intact animals and first control group throughout the entire experiment. While using the OCP-N-Chitosan-Ampicillin material they were higher than the first control group. The potassium content throughout the experiment in both experimental groups was lower than data of first control group. However, when using OCP-N material on day 84, the studied parameter remains significantly lower than in intact animals; with OCP-N-Chitosan-Ampicillin it returns to normal values. Conclusions: The mineral composition of bone tissue undergoes significant changes following a bone-destructive injury, characterized by a substantial increase in calcium, phosphorus, and magnesium levels. The dynamics of sodium and potassium content are less pronounced. When the bone defect is filled with the osteoconductive material OCP-N-Chitosan-Ampicillin, the levels of calcium, phosphorus, magnesium, sodium, and potassium return to normal values by the 84th day after injury

Methods of atomic absorption, flame photometry, and emission spectral analysis were used to study the concentrations of metals in water and major ecosystem components of the Yenisei River upstream of Krasnoyarsk City (conventionally background area). The mean bulk concentrations of Al and Cu in water exceeded the MAC for water bodies used for fishery. Cu concentration in freshwater shrimp was found to be reliably higher than that in the link of primary producers (periphyton), and Cd concentration in caddis fly larvae was found to exceed that in water moss. The maximal concentrations of metals among the examined aquatic organisms were recorded in periphyton. Cr concentration in the muscles of Arctic grayling was found to exceed some international standards.

Modern small-sized spectrometers are mainly designed by the Czerny–Turner scheme with a flat diffraction grating or, if the goal is to obtain the maximum aperture at the expense of resolution, by the scheme with a concave diffraction grating. In such spectrometers, the spectrum is registered by photodiode array. In this work, we provide an overview of characteristics of the compact spectrometers developed by our group. These spectrometers use caseless linear photodiode arrays for spectrum registration that eliminates the reflection of radiation from the cover glass of the photodiode array and reduces stray light. The tightness of the housing of spectrometers prolongs their service life. The parameters of the spectrometer modifications designed according to the Czerny–Turner scheme are given. The main advantage of the spectrometer of this type is the low stray light inside the device and the same spectral resolution throughout the spectral range. Aberrations limit the working aperture in the Czerny–Turner scheme to 1/6. The scheme with a flat field allows operation with a larger working aperture. Three modifications of the spectrometer have been developed according to this scheme; a description of their main parameters is given. The results of experimental comparison of the light gathering power and spectral resolution of spectrometers with different optical schemes, as well as the examples of their application, are presented. Devices designed according to the Czerny–Turner scheme are used in atomic emission and atomic absorption spectral analysis and in spectrophotometry for registration of absorption spectra of condensed media. The spectrometers with flat field are used for recording luminescence and Raman spectra of minerals. The developed compact spectrometers can work in a spectral range of 190–1100 nm with the width of the recorded spectral range from 70 to 1000 nm; the best spectral resolution is 0.1 nm, the stray light level is less than 0.05%, and the maximum measured optical density exceeds 3. Owing to a large working aperture of 1 : 2.1, the flat field spectrometers have an increased light gathering power.

A series of experimental intermittent bottle roll tests was conducted on various content of gold and silver on oxide and sulfide ores at PT Bumi Suksesindo. The ores content variation that was used are high gold with low silver content, low gold with high silver content, both high gold and high silver content, and both low gold and low silver content for each oxide and sulfide ores. The intermittent bottle roll test was carried out at 33% of solids with the initial concentration of NaCN in the solution is 1,000 ppm and maintained at a concentration of 750 ppm. The sample size fraction that was used is -25.0 +0.6 mm with a P80 of 12.5 mm. The pregnant leach solutions were analyzed for the gold and silver concentrations using AAS (Atomic Absorption Spectrophotometer) and also analyzed for the NaCN concentrations by the titration method using AgNO3 (Silver Nitrate). Besides, the remaining solids (tail) were also analyzed for the gold and silver concentrations by the acid digest method (using aqua regia) to determine the metal extraction. The results showed that the highest gold extraction was obtained on the high gold and low silver content of 79.0% for the oxide ore samples and 82.8% for the sulfide ore samples. The gold extraction on the oxide ores tends to be lower than the sulfide ores, and the gold extraction is dependent on the total amount of gold and silver in the ores. The greater the total amount of gold and silver on the ores, the lower the gold extraction obtained for both oxide and sulfide ores. The average NaCN consumption for the sulfide ores is 1.33 kg/t, which almost three times more than the NaCN consumption for the oxide ores, which are on average of 0.46 kg/t.

The study of the material composition of gold-bearing ores includes the determination of quantitative chemical and mineral composition, forms of noble metals, granulometric composition, and physical and mechanical properties to choose the direction for the development of an effective technology of their complex enrichment. This work is devoted to the study of the material composition of refractory gold-bearing ore of Aktobe deposit. It was determined that the content of gold is 1.55-1.6 g/t, the mass fraction of silver is 42-43 g/t, and the content of sulphur is low and is 1-1.1% respectively. Of non-ferrous metals, zinc 0.17%, and lead 0.15% are present in insignificant amounts, and the content of harmful impurities antimony and arsenic are insignificant and amounted to 0.01 and 0.05%. The ore sample has a relatively uncomplicated mineral composition: rock-forming minerals represented by quartz, potassium feldspar, calcite, and mica predominate significantly. Ore minerals are represented by pyrite up to 10 %, limonite up to 0.5 %, galena 0.15-0.2 %, sphalerite 0.17-0.2 % and gold. Physical and mechanical properties of the ore were determined. According to the category of crushability, the ore belongs to the category of medium hardness. According to Bond's method, the "index of network Wi" of ball milling was determined for the initial ore, which was 19.3 kW∙h/t∙μm0.5. Based on the obtained data on the study of material composition, further research will be directed to the study of gravity and flotation enrichment.

We have developed a procedure for quantitative determination of the elemental content (Ca, P, Mg, Fe, Mn, Al, Si, Sr, Ti) in human bone tissue by atomic emission spectral analysis. We have determined the metrological characteristics of this method. We have established the characteristic features of the qualitative and quantitative elemental content in pathology (using as an example bone tissue affected by coxarthrosis).

Graphite is a popular material in the defense, steelmaking, mining industries, and is also used in microelectronics. The balance reserves of graphite in Russia are more than 100 million tons and are concentrated in large quantities in the Urals and Siberia. Natural graphite is associated with silicates and sulfides. The article presents a study of the processing of graphite-shale rock of the Far East. The material composition of graphite-shale rock is represented by silicon, iron, aluminum, calcium, sulfur, carbon, potassium and titanium. The rock is composed of shale, sulfides, carbonate minerals and graphite. The purpose of this work was to study the chemical and physical methods of enrichment of graphite-shale ores to obtain rough graphite concentrate. The objectives of the study were: determination of the material composition, study of acid and flotation separation of crude graphite concentrate, determination of the ash content of the original and obtained products, development of a process flow chart for processing graphite-shale ore. The following methods were used to solve the problems: Clever C-31 X-ray fluorescence spectrometer, ECS 80 series CHNS-O elemental analyzer according to the Dumas method, Levenhuk D95L LCD digital microscope, FMP-L1 flotation machine, EVS 15/5 separator. The original ore is represented by aggregates of isometric, acute-angled shapes, opaque in transmitted light. There is ore material in the form of pyrite. The average size of the aggregates is 95 μm. Acid decomposition of sulfuric or phosphoric acids does not allow obtaining crude concentrates. During acid decomposition, decomposition of sulfide and carbonate minerals and the transition of sesquioxides into solution are observed. During flotation enrichment, the extraction of graphite into the froth product was 75%, which exceeds the graphite content by more than four times compared to the original ore. During the second cleaning by flotation of rough graphite concentrate using diesel oil and polyethyleneglycol, a concentrate with a mass content of graphite of 21.76% was obtained. Magnetic separation of the original ore and enrichment products does not allow adequate separation of the magnetic fraction from the non-magnetic, due to the sulfide form of iron. The ash content of the original rock was determined to be 90.20% and of the rough graphite concentrate - 70.32%. Enrichment tailings are represented by silicates and sulfides. Enrichment waste is recommended to be used as raw material for the production of silicate materials.

Pyrite and arsenopyrite individuals were investigated in ore samples from the mesothermal Klyuchevskoe deposit. The internal structure of the individuals was determined by structural etching. Zoning of two orders was described. A correlation was established between the size of growth layers and the thickness of first-order zones. The anisotropic distribution of minor elements in particular zones and growth sectors was detected. It was found that the internal structure of metacrysts changes regularly, depending on their position relative to productive and nonproductive veinlets of different age. It was shown that, taking into account the volume effects of crystal growth, local changes in the geochemical parameters of mineral-forming medium (variations in trace element concentrations, density of mineral-forming solutions, character of temperature variations, etc.) can be estimated from variations in oscillation periods. The prospects of using pyrite-arsenopyrite and other geothermometers to study crystals consisting of several simple forms are discussed. It was concluded that the characteristics of the internal structure of pyrite metacrysts provide information on the stages of deposit formation.

Introduction and research objective. Copper-zinc ore of pyrite deposits of the Uralian type are refractory. Difficulties in beneficiation are due to their material composition: fine coarseness and emulsion impregnation of ore minerals in each other, a large amount of flotation-active pyrite, a high content of finely dispersed and submicroscopic gold in sulfides, etc. In the course of pyrite ore processing at dressing mills, 83–91% of copper and 10–45% of gold are extracted into copper concentrates, and 46–78% of zinc and 5–15% of gold are extracted into zinc concentrates. Increasing the process performance of pyrite deposit ore processing is a promising and urgent task. Methods of research included copper-zinc pyrite ore material composition study through quantitative chemical analysis, chemical phase analysis for the forms of copper, zinc, gold and silver compounds, and mineralogical analysis. Technological studies were carried out by flotation and gravity methods using a centrifugal concentrator and a concentration table. Conclusions. In the course of pyrite deposit copper-zinc ore beneficiation at the dressing mill, the effect of circulating concentration of gold in the coarse copper concentrate regrinding cycle was established. The results of studies on the centrifugal concentration of gold in a centrifugal concentrator with further secondary cleaning of its heavy fraction on a concentration table show the possibility of obtaining a gravity product with a mass fraction of gold up to 200 g/t under its operational extraction up to 29%. It was noted that the integrated flotation-gravity technology for copper-zinc ore beneficiation will increase the through extraction of gold into marketable mineral products by more than 1.5%. The use of a combination of butyl potassium xanthate and FRIM-2920 reagent-collector in the copper-zinc pyrite ore flotation technology contributes to increased extraction of copper and gold into copper concentrate by 0.87% and 3.22%, respectively, and zinc into zinc concentrate by 0,4%. Increasing the pulp temperature in the zinc flotation cycle to 40–45 °C and returning the control zinc flotation concentrate and tailings from the first cleaning flotation of zinc to the II main zinc flotation allows increasing the mass fraction of zinc in the zinc concentrate from 48.5 to 51.1% under a simultaneous increase in the extraction of zinc into zinc concentrate from 62.6 to 65.6%.

Utilization of high-gradient magnetic separation–secondary grinding–leaching to improve the copper recovery from refractory copper oxide ores

Opaque mineralogy and resource potential of placer gold in the stream sediments between Duba and Al Wajh, Red Sea coast, northwestern Saudi Arabia