Method of assay determination of content of gold in ores and in products of their processing |
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IPC classes for russian patent Method of assay determination of content of gold in ores and in products of their processing (RU 2288288):
Method of determination of content of palladium and platinum in ores / 2283356
Proposed method includes decomposition of ore by hydrofluoric and nitric acids followed by further decomposition by aqua regia, boiling-off to moist salts, dissolving of them in hydrochloric acid and extraction. Determination of content of palladium is carried out in organic phase thus obtained and that of platinum is carried out in hydrochloric acid phase. Extractants used for such determination are s-alkylisothiouronium halides and alcohols of C5-C8 fractions, as well as kerosene, benzene, toluene and xylols used as diluents. Used as s-alkylisothiouronium halides are chlorides, bromides and iodides from C7 to C14 and their fractions.
 Method of determination of cause of low impact viscosity of low-carbon steels / 2281975
Proposed method consists in finding-out dependence of grain size of microstructure and presence of ferrite net, as wells as marks on bearing faces of tested specimens for products of the same type made from steel of definite quality during analysis of causes of low impact viscosity recommended standards are established for these parameters and dependences thus found are compared with the data of specimens of low (below standard norm) impact viscosity and these data are estimated for compliance with the recommended standards. Dependences thus found are used repeatedly and constantly.
 Method of a quality control over the test crucible melting / 2272850
The invention is pertaining to nonferrous metallurgy, in particular, to the methods of detection of the noble metals in the mineral raw materials. The technical result of the invention is an increased trustworthiness to the results of the testing crucible melt analysis. The method is conducted in the following way. From the material of the laboratory test sample take out the analytical part of the filler, mix it with the calculated amount of the charge and the mixture is smelt according to the standard method. During the smelt visually control the height of the boiling layer of the melt slag and lead. On completion of the smelt measure the mass of the slag and lead and calculate an admissible height of the boiling layer of the melt according to the following formula:0,9·Hm≥Hc≥[1,9/tg2α/2·(Mш/ρш+Mc/ρc)]1/3, whereHcr - depth of the crucible in meters(m);Hsl - the height of the boiling gas-slag layer, m; α - an angle at the apex of the cone of the inner surface of the crucible, in degrees;Msl, Mla - masses of the slag and mass of the lead alloy accordingly, kg;ρsl, ρla - density of the slag and density of the lead accordingly, kg/m3. If the visual estimation of the height of the boiling layer of the melt exceeds the limits of admissible values, them one may draw a conclusion about the low quality of the testing smelt, make corrections in the composition of the charge and repeat the test analysis.
 Method of preparing samples for analysis / 2267111
Method comprises sampling initial material, producing and analyzing group samples before assessing representative mass of analytical samples, estimating representative mass of analytical samples, and calculating the value of the coefficient that characterizes the type of gold-bearing material from the formula proposed.
 Method for determining hardness limit of austenite class steel / 2265213
Method includes subjecting samples of steel to preliminary plastic deformation and on basis of wear test results of pre-deformed samples, graph of change of hardness limit of σ-1 samples is built dependent on their level of pre-deformation. Weighed samples are made with same deformation level and value of magnetic tear force Pmag is determined for each weighed sample. Graph of change of magnetic tear force Pmag is built for samples on basis of their pre-deformation level, graph with adjusting curve in coordinates Pmag - σ-1, setting a connection between Pmag and σ-1 dependent on level of pre-deformation. Hardness limit of σ-1 samples is determined by adjusting curve in coordinates Pmag - σ-1.
 Method of measuring duration of serviceability of metals / 2261436
Method can be used for estimation of deformation-strength properties due to applying load as well as for determining damages by means of X-ray diffraction analysis. Values of structural-sensitive parameter of crystal lattice of tested material are determined by X-ray diffraction analysis in initial and post-deformation states. Deformation-strength characteristics of metal are determined by calculation from changes in structural-sensitive parameter. Serviceability is judged by comparing really achieved characteristics with admissible ones. Width of X-ray line β is used as structural-sensitive parameters. Strength of deformation P, deformation Δl provided by the deformation and corresponding values of structural-sensitive parameter β are registered during testing. Dependence of true stresses S and structural-sensitive parameter β on degree of relative residual deformation δ are calculated on the basis of P and Δl. Destruction diagram (S-δ½) and linearized diagram (β½-δ½) are built to show inflection points. Deformation-strength characteristics SD and δD corresponding to inflection point at destruction diagram (destruction point D) is taken as criterion of admissible surface strength which provides maximal serviceability of metal. Factor of merit η and factor of destruction Δ can be also taken as criteria of serviceability of metal.
 Mode of testing railway rails on contact weariness / 2253112
Contact weariness is induced by high-frequency dynamic components of interaction of wheels and rails, which become apparent at moving at high speed. The mode of testing railway rails on contact weariness is in that tested samples of rail steel are rolled by pinch rolls in longitudinal direction until appearance on the surface of the sample of dents and also deep indents. As samples test rails are used. The diameter of a pinch roll is chosen under condition of equality of reduction ratio of linear size of the site of contact of the pinch roll with the rail along the axis of the last in comparison with corresponding size responsible to conditions of exploitation and speed reduction ratio of rolling motion of the pinch roll along exploited rail.
Material for production of assay stone / 2248336
Assay stone is made from oxide ceramic comprising BeO-TiO2. Material affords the ability to obtain assay stone of regular geometric form with surface, electrical and mechanical properties meeting the requirement for material used in assaying control. Claimed material in useful in standard determination followed by electrochemical recovery of precision metals from solution after assaying control.
 How kopaliani lead alloys containing gold and silver, assay analysis / 2237734
The invention relates to the field of analytical chemistry and can be used in the assay analysis for separating precious metals from lead
 Method of preparation of analytical weighted portion of gold-bearing ore for assay / 2283357
Proposed method includes selection of analytical weighted portions from ordinary samples of ore, analysis of weighted portions, forming and analysis of group sample before estimation of mass of weighted portion, estimation of mass of weighted portion, selection of weighted portion from sample at size of grain of 1-0.04 mm and final grinding of weighted portion to 0.2-0.04 mm. During analysis of weighted portions, approximate magnitude of content of gold Co.s. in ordinary samples is determined, group sample is formed from ordinary samples at minimum content of gold, analytical weighted portions are taken from group sample and content of gold Ci is determined, average content of gold in group sample Cg.s. is calculated, minimum mass of analytical weighted portion for group sample Mg.s.(g) is set at ratio Пi=2(Ci-Cg.s.)/(Ci+Cg.s.)≤Дg.s., where Пi is relative discrepancy between content of gold in i-analytical weighted portion and average content of gold in group sample; Дg.s. is permissible relative discrepancy between results of determination of content of gold in group sample during laboratory monitoring; then estimation of mass is performed for ordinary samples Mo.s. by the following formula: Mo.s.= (Mg.s..Дg.s./(Co.s..Дo.s.), where Дo.s. is permissible discrepancy between results of determination of content of gold in ordinary sample during laboratory monitoring.
 Method for noble metal recovery / 2276196
Claimed method includes disintegration of radio-electronic debris, vibrating treatment with separation of heavy fraction containing noble metals, metal separation and recovery, wherein radio-electronic debris is sorted, and metal components are separated, remaining debris part is treated with separation of heavy fraction. Said fraction after separation is mixed with preliminary separated metal components and mixture is subjected to oxidative melting with feeding of air blowing in amount of 1.15-0.25 nm3 per 1 kg of mixture. Further obtained alloy is electrolitically refined in copper sulfate solution and noble metals are recovered from formed slurry. Method of present invention makes it possible to isolate 98.2 % of gold, 96.9 % of silver and 98.2 % of platinum.
Method of a quality control over the test crucible melting / 2272850
The invention is pertaining to nonferrous metallurgy, in particular, to the methods of detection of the noble metals in the mineral raw materials. The technical result of the invention is an increased trustworthiness to the results of the testing crucible melt analysis. The method is conducted in the following way. From the material of the laboratory test sample take out the analytical part of the filler, mix it with the calculated amount of the charge and the mixture is smelt according to the standard method. During the smelt visually control the height of the boiling layer of the melt slag and lead. On completion of the smelt measure the mass of the slag and lead and calculate an admissible height of the boiling layer of the melt according to the following formula:0,9·Hm≥Hc≥[1,9/tg2α/2·(Mш/ρш+Mc/ρc)]1/3, whereHcr - depth of the crucible in meters(m);Hsl - the height of the boiling gas-slag layer, m; α - an angle at the apex of the cone of the inner surface of the crucible, in degrees;Msl, Mla - masses of the slag and mass of the lead alloy accordingly, kg;ρsl, ρla - density of the slag and density of the lead accordingly, kg/m3. If the visual estimation of the height of the boiling layer of the melt exceeds the limits of admissible values, them one may draw a conclusion about the low quality of the testing smelt, make corrections in the composition of the charge and repeat the test analysis.
Method of extraction of noble metals / 2272084
Proposed method increases degree of extraction of noble metals into alloy at eutectic melting due to increased degree of extraction of micro-dispersed phases (nano-particles) and atoms of noble metals found in dislocations (linear defects) and micro-cracks of crystal lattices of initial materials. To this end, material from which noble metals are to be extracted is mixed with charge of alkaline composition and mixture is subjected to eutectic melting, thus obtaining alloy of these metals. Immediately before melting, mixture is subjected to mechanical activation continued for 0.0833-2 h at maintenance of ratio of delivered mechanical energy power to relative surface of mixture within 0.0133-25 W x kg x m-2. Eutectic melting of mixture is performed at temperature above 500°C. Ratio of mass of charge to mass of material is selected within 0.75-2; used as charge is mixture of sodium tetraborate with sodium carbonate, sodium tetraborate with sodium bicarbonate, sodium tetraborate and sodium carbonate and lead mono-oxide, sodium tetraborate with sodium bicarbonate and lead mono-oxide.
 Method of production of silver from silver chloride by reduction with gaseous hydrogen / 2265673
Proposed method includes reduction of silver chloride at heating and holding at heat in flow of gaseous hydrogen, bubbling of gas escaping from reaction chamber through water and obtaining aqueous solution HCl. Reduction is performed from silver chloride formed at refining of noble metals and ground to size of ≤100 mcm and located in reaction chamber at thickness of layer of ≤20 mm at temperature of 450°C±5°C by gaseous hydrogen heated to holding temperature.
Method for processing products containing non-noble metal chalcogenides, platinum group metals and gold / 2260629
Method comprises steps of treating material with nitric acid solution till oxidation-reduction potential 500-700 mV; extracting non-soluble residue; melting it at adding sodium-containing fluxes, carbon -containing reducing agent and copper- and(or) iron-containing industrial process product obtained at hydrolysis or cementation treatment of solutions of refining production; settling and cooling melt till its solidification. Solidified product is separated according to interface boundaries. Then separated bottom phase of heavy alloy is disintegrated to powder. Method allows to extract to target alloy up to 94% of platinum and palladium, more than 97% of rhodium, iridium and ruthenium. Disintegrated alloy may be processed as concentrate of refining production.
Method of recovering gold from gold ore concentrates / 2259410
Invention relates to selective recovery of gold from gravitation and flotation concentrates of gold-recovery fabrics in the stage of adjusting gold-containing products to condition meeting affinity requirements. Method of recovering gold from gold ore concentrates into lead melt comprises dispersing molten lead at vigorous blade agitator-mediated mechanic stirring in common with gold-containing concentrate in presence of molten alkali (NaOH) at concentrate-to-alkali weight ratio 1:(1-3) and temperature 400-550°C depending on mineralogical composition of concentrate.
Method of recovering silver from waste / 2258091
Recovery of silver from waste, such as spent catalysts and ashes, us accomplished by charging waste into soda-borax melt taken in such proportions that weight of soda is by 2.0-3.5 times superior to that of oxide constituent of starting material and weight of borax constitutes 8-20% that of soda. Melting is effected at 1120-1350°C and melt is aged then for at least 15-20 min, after which products are separated and silver is recovered. Weight of charged waste (Pw) is found in dependence of content oxide constituent therein using formula (wt %): Pw = (11.5-16.7)MeO+(0.5-1.0)Na2B2O7+9SiO2 ( Me is Ca, Al, or 2Na).
Method of separating multicomponent material containing metallic components / 2248406
Multicomponent waste material is preliminarily impregnated with solution of salt of metal-collector in amount ensuring weight content of metal-collector in melt exceeding content of metallic components therein. Material is then calcined and melted in reductive atmosphere after addition of slag-forming flux based on metal fluorides. Melt is stirred and kept in liquid state over a period of time long enough to allow separation of slag and metallic phases. Resulting slag and metal are tapped and mechanically separated when solidified.
Gold content determination in gold-containing raw material / 2245931
Claimed method includes sampling the probe of starting material, grinding, mixing with massicot, smelting to form bullion, parting of gold-silver globule, weighting of gold sinterskin. Probe is sampled from starting natural solid organic material. Before smelting mixture is packaged in lead foil, established in full-hot scorifying dish, and padded with borax and table salt.
Gold content determination in gold-containing raw material / 2245931
Claimed method includes sampling the probe of starting material, grinding, mixing with massicot, smelting to form bullion, parting of gold-silver globule, weighting of gold sinterskin. Probe is sampled from starting natural solid organic material. Before smelting mixture is packaged in lead foil, established in full-hot scorifying dish, and padded with borax and table salt.
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FIELD: analytical chemistry of noble metals; assay analysis; determination of content of gold in ores of different mineralogical composition and in products of their processing (tailings, concentrates). SUBSTANCE: proposed method includes melting of starting material with lead oxide, soda, borax and flour for obtaining lead alloy (crude lead), its cupellation till gold-silver regulus, dissolving of silver in diluted nitric acid and determination of amount of gold by weighing or by any other instrumental method. Melting process is carried out in metal crucibles at temperature of 600-800°C for 10-30 minutes; charge per 10 g of sample contains the following components: 20-50 g of sodium or potassium hydroxide; 2-20 g of borax; 1-10 g of soda; 15-30 g of litharge and 1-3 g of flour. Method is recommended for assay of samples having mass of 10-100 g. EFFECT: facilitated procedure and low cost of assay. 1 tbl
The invention relates to the field of analytical chemistry of the noble metals (BM), namely the assay analysis, and can be used for determination of gold in ores of different mineralogical types and products of their processing. The essence of the assay analysis consists in fusing the sample analyzed material with flux and collector. The main part of the breed (macronutrients) associated with flux and passes into the slag. Precious metals are quantitatively transferred into the collector. Hot water poured into the mold. After cooling the collector is separated from the slag and sent for further chemical processing with subsequent determination of BM. Melting is carried out in a powerful furnaces special design (crucible furnaces) at a temperature of 1000-1200°C for 1-2 hours. As fluxes usually use baking soda, borax, quartz. As collectors use a variety of metals and sulfides of metals. The composition of the charge collector is introduced in the form of a metal oxide or sulfide, or metal and sulfur. For recovery of metal oxide to metal collector a necessary part of the charge is the reducing agent. Current top in most of these reducing agents is carbon (charcoal, flour, bran, starch, sugar, paper). Scheme of chemical processing collector determines the tsya collector type. View of the final instrumental analysis scheme determines the chemical processing of the header and content of BM in the final concentrate. A known method of assay concentration of gold in tin Wren followed by atomic absorption determination (Navsarka, Nsamba, Towpackage and other Concentration of gold and silver in tin Wren to further their determination by atomic absorption spectrometry. Proceedings of TsNIGRI, 1981, No. 157, p.78-82). Crucible melting is carried out at a temperature of 1200-1250°within hours. The composition of the charge is tin dioxide (40 g), soda (50 g), silica (15 g), fused borax (10 g), flour (40 g). The weight ratio of the weighed sample and mixture 1:7,5. The resulting tin alloy is dissolved under heating in a mixture of hydrochloric and nitric acid (5:1), the solution evaporated several times with the addition of the same lump to remove SnCl4translate to chlorides by three-time processing of hydrochloric acid and hydrogen peroxide with an intermediate evaporation to moist salts. Further salt was dissolved in 1M HCl and sent for atomic absorption analysis. The disadvantages of this method is the high temperature fusion and complexity acid treatment, since the dissolution goes the whole tin alloy, obtained by crucible smelting. A known method of assay concentration angry is that in copper alloy with subsequent atomic absorption determination (Diamantatos A. Fire-assay collection of gold and silver by copper. Talanta, 1987, 34, No. 8, R-738). The method includes annealing at 750°sample sample mass of 1-3 g, mixing it with flux (40 g of CuO, 25 g of borax, 60 g sodium, 10 g silica, 2 g of graphite) and melting at a temperature of 1200°C for 1.5 hours. The obtained copper alloy weighing 30 g dissolved in 300 cm3perchloric acid under heating for 2 hours, after addition of acetic acid is boiled for a further 1 hour. After cooling, the solution stand in the dark for 1.5 hours, filtered, the precipitate to the filter is dissolved in Aqua Regia boiling. The resulting solution is evaporated to dryness with sodium chloride, the salt is dissolved by boiling in hydrochloric acid with the addition of hydrogen peroxide and translated into the volume of 3M hydrochloric acid. The solution is directed to the atomic-absorption determination of gold. Disadvantages of the method are the high temperature fusing, the need for pre-roasting, small sample tests (nepredstavitelne sample) and the complexity of the acid treatment, since the dissolution goes the whole copper alloy, obtained by crucible smelting. A known method of assay concentration of gold and platinum group metals in the copper-Nickel reservoir with subsequent atomic emission determination (Paydayloa, Ihavenolife, Ramnagaram. Assay-chemical-spectral about what the definition of platinum group metals and gold in sulfide copper-Nickel ores and products of their processing. Laboratory, 1982, 48, No. 8, p.9-10). The method developed for the analysis of sulfide copper-Nickel ores. A necessary preliminary step in the scheme of assay determination of such ores is the burning of the sample (weight of 30-100 g) at a temperature of 850°C for 7 hours. Crucible melting burned samples is carried out at a temperature of 1200°C for 1-1 .5 hours. The charge is calculated on the formation of Cu-Ni collector with a mass ratio of Cu:Ni≥2:1 (add CuO with regard to the content of copper and Nickel in the ore). Other components of the mixture per 100 g ore: anhydrous soda - 95 g of fused borax - 250 g glass - 25 g, starch - 20 was Obtained Cu-Ni alloy (translated in chips) is dissolved in 50 cm3hydrochloric acid added dropwise hydrogen peroxide, the solution is filtered. The filter residue silaut, fusion with sodium peroxide, water leached 6M HCl. All solutions combine, evaporated and transferred in 1M HCl. Platinum metals and gold adsorb from solution on activated carbon and the sorbent PVB-MP-20T and determine the content of atomic-emission method. Disadvantages of the method are the high temperature fusing, the need for pre-firing and the complexity of the acid treatment, since dissolution is sent to all Cu-Ni alloy, obtained by crucible smelting. Known assay method concentrated the I gold and platinum group metals in Nickel matte and subsequent atomic emission inductively coupled plasma determination (instruction NSAM No. 366-s Atomic emission inductively coupled plasma determination of platinum, palladium, rhodium, iridium, ruthenium and gold in sulfide copper-Nickel ores and products of their processing with pre-concentrated in Nickel matte". M, 1995). The method developed for the analysis of sulfide copper-Nickel ores. The method includes crucible melting weighed samples (0.5 to 100 g) with the charge to produce Nickel matte, acid dissolution collector, analysis undissolved residue containing in itself all precious metals. Crucible melting is performed at a temperature of 1000-1100°C for 1 hour. In charge is injected Nickel oxide and sulfur for the formation of the collector (the calculation is performed on education matte weight of about 20 g on empirical formulas with regard to the content of sulfur in the ore and Nickel) and fluxes: soda ash 50-120 g borax 25-60 g, glass 0-60 g (compositions of fluxes depending on the mass of the weighed sample is shown in table). In order to reduce losses BM method involves melting slag flux and Nickel sulfide. United matte is crushed, selected sample (mass of a sample is selected in accordance with table and is 10-15 g), treated with concentrated hydrochloric acid (200-250 cm3) when heated, separated by filtering any insoluble sulfides BM that translate into solution by boiling in Aqua Regia and then to chlorides by mnogokrat the nd evaporation with the addition of hydrochloric acid. The resulting solution BM (on the basis of hydrochloric acid 1:5) is directed to atomic emission determination (spectrometer with plasma excitation source company FCD, model 3580. Disadvantages of the method are the high melting temperature, the need for processing of almost all of the mass obtained Stein, the complexity acid treatment. A common disadvantage of the above methods is the need for time-consuming acid treatment all received in the process of melting the mass of the collector, which, as a rule, comparable to the mass of the sample. This drawback is devoid method of assay concentration of gold in lead collector (free), which includes (in addition to the melting crucible) operation Kopaliani free, i.e. its oxidation melting on Kabalah: the lead is oxidized to oxides, which are selectively absorbed in the molten state in the material drops - magnesite, bone meal, etc. So cupellation allows you to completely remove the lead from free to get gold-silver bead small mass. To obtain a lead collector in the composition of the charge additionally include litharge (low-temperature modification of oxide of lead), which when heated with a reducing agent in the process of melting crucible readily gives up oxygen with formation of metallic light of the CA (melting point 327° C). Litharge is both highly basic flux and forms a fusible silicates, easily dissolving the metal oxides. In the presence of sulfur in the sample litharge is also desulfurization. The known method of assay determination of gold and silver ion-exchange resins (Ubicare, Submicron, Waggonbau, Avenarius. "Method for determination of gold and silver ion-exchange resins". Copyright certificate №1547319, MKI 22 In 3/00, publ. 01.11.1989, priority from 11.12.1987 year). The method includes drying the saturated resin at a temperature of 60-80°its melting when 890-940°in the presence of borax, litharge, nitrate to obtain zolotopererabatyvayuschego lead alloy. While nitrate is introduced in a quantity of 0.5-0.6 by weight of the resin and litharge, taken on 20 units of mass greater than the mass of nitrate (an example is shown on a portion of the dried resin weight 24 g with a mixture of nitrate - 13 grams of litharge - 33 g of borax - 5 g). The free kapelrud to obtain gold-silver goldcrest, which weighed, razvarivat in nitric acid to Golden squat, which burn and re-weighed. The disadvantages of the method are its oncospecific direction: the composition of the charge and the melting temperature is only suitable for the analysis of resins. The known method of assay determination of gold (ISO 10378 International Standart "Concentres de sulfures plomb - Dosage cte D'argent et de for - Methode par voie seche et spec trometrie d asorption atomique dans la flamme a partir d'une coupellation. First edition 1994-06-11. The reference number ISO 10378:1994 (E)), which includes assay crucible melting samples pre°with the charge on the basis of soda, borax, litharge, reductant to obtain lead alloy (free), cupellation to gold-silver goldcrest, dissolution of silver in dilute nitric acid and the weighting of the resulting gold squat. If the mass of the gold squatting less than 0.005 mg it is dissolved in a mixture of nitric and hydrochloric acids and determine gold by the method of flame atomic absorption spectrometry. The method developed for concentrates of copper sulfide, resulting in the charge injected additional quantity of litharge and nitrate (20 g samples of 30 g of sodium, 210 g of litharge, 25 g of silicon dioxide; the mass of nitrate calculated by the resilience of the sample and determine the control melting). The closest analogue in essential characteristics and purpose is: Probootborniki and analysis of noble metals, edited by Iframename. M., "metallurgy", 1968, 121-132, 154 C, in which is disclosed a method of assay determination of gold in ores and products of their processing, including melting at a temperature of 1150°With the charge from the sample source material with litharge, soda, brown and flour with getting lead alloy, it cupellation to gold-silver goldcrest, dissolving the sulfur is RA in dilute nitric acid and determining the quantity of gold obtained by weighing the gold squatting or instrumental method. The objective of the invention is to simplify and accelerate the analysis, as well as reducing its cost by reducing the duration and temperature of fusion of the sample, increasing the service life of furnace, reusable metal crucibles. The technical result is achieved in that in the method of assay determination of gold in ores and products of their processing, including the melting of the charge from the sample source material with litharge, soda, brown and flour with getting lead alloy, it cupellation to gold-silver goldcrest, dissolution of silver in dilute nitric acid and determining the quantity of gold obtained by weighing the gold squatting or instrumental method - in charge is injected sodium hydroxide or potassium in the composition of the mixture, 10 g of sample: 20-50 g of sodium hydroxide or potassium, 2-20 g of borax, 1-10 g soda, 15-30 g of litharge, 1-3 g of flour, and a heat conducting metal crucibles for 10-30 minutes at a temperature of 600-800°C. The recommended method for analysis of samples by weight of 10-100 g Technical implementation of the method The mixture for the assay alkaline fusion is prepared by weighing the individual components on a technical scale (0.1-0.01 g) and subsequent mixing, which produces well-known methods (mixing with a spatula. then rolling the sheet to which LCI; mixing in a closed jar or plastic bag and so on), in this first mix the sample, soda, litharge, borax, flour, then add the lye and mix again. The prepared mixture is poured into a metal crucibles (the fill factor of 0.2-0.4), which is placed in a heated to a predetermined temperature oven and leave in oven set time, take out and not cooling water, pour it into a metal mold. After cooling the mold overturn and easy to remove from her frozen water 1-2 blows on the anvil. Then the hammer is separated from the slag lead alloy. The resulting free kapelrud to gold-silver goldcrest, dissolved silver in dilute nitric acid and determine the amount of gold obtained by weighing the gold squatting or other instrumental method (for example, dissolve gold kartochka in acids and analyze the solution by atomic absorption). One of the advantages of the inventive method is used for alkaline melting metal crucibles instead of fireclay crucibles used in the classical assay analysis, which are made on special order and re-used is usually not more than 3-5 times (with the possible contamination of the samples). Metal crucibles can be used many times: after melting (after disposing of taperapua) they are placed in a large tank of water (for example, barrel) and leave for a few hours. The solidified slag is partially dissolved and otmechaet". The crucibles are easily cleared from the wet slag. Sticking balls of lead alloy to the walls and bottom of the washed crucibles is not observed. Thus, contamination of subsequent samples of the remains of the previous does not occur. Prepared by the above method crucibles can be used for the following heats. The main advantage of the claimed method is the use of low-melting of the charge, which reduces the melting temperature at 200-400°and the time of fusing reduced to 10-30 minutes. This significantly increases the service life of furnaces, performance analysis and, therefore, reduces the cost of analysis. For melting can be used not only special furnace designs (designed for this method of fusion), but also assay crucible and conventional muffle furnace. The table shows the results of the analysis of the claimed method (final operation - weighing gold squatting) number of standard samples and samples Pokrovsky mine. The mineralogical composition of the samples is as follows: - granite-porphyries with veins of quartz (sample Pokrovsky mine), - quartz gold-silver ore RGU-6 (GSO 5806-91), - gold sulphide ore WA-6 (CCA 283-96). For sravneniyami Pokrovsky mine analyzed in the assay analytical laboratory OJSC Pokrovskiy Rudnik (Amur region, Blagoveschensk) certified by the method of classical assay analysis. Thus, when verifying the claimed method was used limitedly interlaboratory experiment two independent methods, and two independent laboratories.
As can be seen from the table, the results of determination of gold by the claimed method differs from the classical results of assay analysis within the most stringent (P=0,68) permissible error analysis DSS.=With·σD,r:100, g/t, where C is the content of the component to be determined in the sample, g/t, σDGpermissible relative standard deviation of the results of the analysis performed by the methods category III classification (standardized for OST 41-08-212-82), %. Absolute tolerance is calculated according to the gold content in the sample, a specific certified by the method of classical assay analysis. Method of assay determination of gold in ores and products of their processing, including the melting of the charge from the sample source material with litharge, soda, brown and flour with getting lead alloy, it cupellation to gold-silver goldcrest, dissolution of silver in dilute nitric acid and determining the quantity of gold obtained by weighing the gold squatting or instrumental method, characterized in that the charge injected sodium hydroxide or potassium in the composition of the mixture of 10 g of the sample: 20-50 g of sodium hydroxide or potassium, 2-20 g of borax, 1-10 g soda, 15-30 g of litharge, 1-3 g of flour, and melting is carried out in m is a metallic crucible for 10-30 minutes at a temperature of 600-800° C.
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