Study of biohydrometallurgical technology used to recover gold from ore at a gold-recovery plant

The article contains the results of the studies performed for the biochemical eхtraction modes for mineral raw materials using thionic bacteria Acidithiobacillusferrooxidans of a certain strain capable to oxidize sulfide minerals. A representative sample of mineral raw materials was taken, and its physical and chemical studies were performed. The optimal conditions to leach mineral raw materials with biochemical solvents based on various factors (temperature, S:W) were established. Modern physical and chemical methods of analysis were used during the study: X-ray fluorescence, X-ray phase, mineralogical, electron probe, chemical analyzes, IR methods to study the phase composition of ores and changes in the structure of minerals. The chemical composition of the ore sample quartered and crushed up to a size of -0.074 mm is as follows, wt. %: SiO2 - 60.11; Al2O3 6.2; Zn 0.016; Cu 0.10; Fe - 2.5; S 0.50; Au - 3.67 g/t and Ag - 3.2 g/t. This paper discusses various options for agitational leaching with acid pre-wash, bacterial dissection and oxidative decomposition of minerals using sodium hypochlorite. The results obtained showed that the most effective method to increase the gold recovery is to perform bacterial oxidation of ore using acidophilic bacteria At. Ferrooxidans preliminarily adapted to the material composition of the test sample, followed by treatment with sodium hypochlorite solution and cyanidation. Biohydrometallurgical ore processing provides high gold recovery (78.1%).

Download Full-text

Analysis of Basic Physical and Chemical Characteristics of Manganese Slag before and after Solidification and Its Feasibility as Highway Slope

Materials ◽

10.3390/ma14195530 ◽

2021 ◽

Vol 14 (19) ◽

pp. 5530

Author(s):

Meng Chen ◽

Jianming Wei ◽

Runhua Zhang ◽

Lipei Jia ◽

Qiqi Yao ◽

...

Keyword(s):

Construction Projects ◽

Raw Materials ◽

Chemical Properties ◽

Guizhou Province ◽

Particle Analysis ◽

Material Strength ◽

X Ray ◽

Electrolytic Manganese ◽

Manganese Slag ◽

Physical And Chemical

Manganese slag is a kind of industrial waste produced by electrolytic production of manganese metal. The traditional method of stacking manganese slag not only causes waste of resources, but also produces environmental pollution. Finding harmless, effective, and economical disposal technology of manganese slag has gradually become a research hotspot and difficulty in the field of electrolytic manganese industry and environmental protection. To verify the feasibility of using manganese slag as roadbed material, the basic physical and chemical properties of manganese slag were analyzed based on X-ray diffraction, X-ray fluorescence spectrum, SEM scanning electron microscope, and particle analysis, the basic engineering characteristics of raw materials of manganese slag and solidified manganese slag mixed with quicklime were analyzed through a compaction test and a CBR test. Finally, based on the Monte Carlo method, the stability of a highway slope in the Guizhou Province of China is simulated by the finite element method, considering the spatial variability of manganese slag material strength parameters. The results show that the solidified manganese slag material can be used as highway subgrade material. This study has important reference significance for manganese slag highway construction projects.

Download Full-text

PHYSICAL AND CHEMICAL STUDIES OF OVERROOF ROCKS OF CLAY SHALES OF THE DZHERDANAK DEPOSIT

CHEMISTRY AND CHEMICAL ENGINEERING ◽

10.51348/ubco8703 ◽

2021 ◽

pp. 16-21

Keyword(s):

Electron Microscopy ◽

Fine Structure ◽

Chemical Properties ◽

Mineralogical Composition ◽

Physical And Chemical Properties ◽

X Ray ◽

Clay Shales ◽

Chemical Studies ◽

Physical And Chemical ◽

And Chemical Properties

The purpose of this study is study of the physical and chemical properties of the overburden of the Dzherdanak deposit. The chemical and mineralogical composition of the overburden of the Djerdanak deposit has been studied by the methods of X-ray and thermography, electron microscopy and infrared spectroscopy. The main phases are quartz, kaolinite and muscovite. The study of the fine structure of the rock under an electron microscope showed the homogeneity of the rock with pronounced uniform inclusions, which is preserved even after firing. Changes in the rock after firing at 1050 °C have been determined. The formation of mullite at this temperature has been established.

Download Full-text

Use of basaltic waste as red ceramic raw material

Cerâmica ◽

10.1590/0366-69132016623621955 ◽

2016 ◽

Vol 62 (362) ◽

pp. 157-162 ◽

Cited By ~ 4

Author(s):

T. M. Mendes ◽

G. Morales ◽

P. J. Reis

Keyword(s):

Size Distribution ◽

Mechanical Performance ◽

Raw Materials ◽

Raw Material ◽

Metropolitan Region ◽

X Ray Diffraction ◽

X Ray ◽

Microstructure Evaluation ◽

Firing Shrinkage ◽

Physical And Chemical

Abstract Nowadays, environmental codes restrict the emission of particulate matters, which result in these residues being collected by plant filters. This basaltic waste came from construction aggregate plants located in the Metropolitan Region of Londrina (State of Paraná, Brazil). Initially, the basaltic waste was submitted to sieving (< 75 μm) and the powder obtained was characterized in terms of density and particle size distribution. The plasticity of ceramic mass containing 0%, 10%, 20%, 30%, 40% and 50% of basaltic waste was measured by Atterberg method. The chemical composition of ceramic formulations containing 0% and 20% of basaltic waste was determined by X-ray fluorescence. The prismatic samples were molded by extrusion and fired at 850 °C. The specimens were also tested to determine density, water absorption, drying and firing shrinkages, flexural strength, and Young's modulus. Microstructure evaluation was conducted by scanning electron microscopy, X-ray diffraction, and mercury intrusion porosimetry. Basaltic powder has similar physical and chemical characteristics when compared to other raw materials, and contributes to ceramic processing by reducing drying and firing shrinkage. Mechanical performance of mixtures containing basaltic powder is equivalent to mixtures without waste. Microstructural aspects such as pore size distribution were modified by basaltic powder; albite phase related to basaltic powder was identified by X-ray diffraction.

Download Full-text

High-strength fluoroanhydrite composition

The proceedings of the 13th international conference "Modern Building Materials, Structures and Techniques" (MBMST 2019) ◽

10.3846/mbmst.2019.042 ◽

2019 ◽

Author(s):

Grigory Yakovlev ◽

Jadvyga Keriene ◽

Valery Grakhov ◽

Rostislav Drochytka ◽

Anastasiya Gordina ◽

...

Keyword(s):

Water Resistance ◽

Raw Materials ◽

Waste Product ◽

High Strength ◽

Structure And Properties ◽

X Ray ◽

Physico Chemical ◽

Gypsum Plaster ◽

Chemical Studies ◽

Increased Strength

The research studies the properties of a high-strength anhydrite composition based on fluoroanhydrite, a waste product of hydrofluoric acid. To activate fluoranhydrite, Na3PO4 sodium phosphate was added to the composition in an amount of 3% of the mass. The physico-chemical studies of the structure and properties of activated fluoroanhydrite conducted using infrared spectroscopy and X-ray phase analysis showed changes in the composition of the hardened composite, and the study of the fluoroanhydrite microstructure revealed the formation of a denser matrix with the increased strength. An increase in the water resistance of the developed binder matrix was noted. The composition can be used as a cheap substitute for gypsum plaster due to the low prime cost of raw materials, and also contribute to the improvement of the environmental situation in fluoroanhydrite disposal sites.

Download Full-text

Glass-Ceramics Obtained from Sewage Sludge and its Characteristics Affected by Alkalinity

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.937.70 ◽

2014 ◽

Vol 937 ◽

pp. 70-73

Author(s):

Di Wu ◽

Jun Zhang ◽

Xing Wang Wen ◽

Hui Ling Liu

Keyword(s):

Sewage Sludge ◽

Raw Materials ◽

Glass Ceramics ◽

Chemical Properties ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

X Ray ◽

Sludge Disposal ◽

Physical And Chemical ◽

And Chemical Properties

Sewage sludge was tested as component for producing glass-ceramics with the addition of analytic reagent CaO to solve the sewage sludge disposal problems. The effect of alkalinity (Ak=mCaO/mSiO2) on the characteristics of the glass-ceramics was investigated. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used to investigate thermal behavior and crystalline phase of the samples. It was found that the degree and characteristics of crystals in vitrified sludge significantly correlate to the alkalinity of the raw materials. The glass-ceramics with Ak = 0.36 possessed the best physical and chemical properties.

Download Full-text

Minerālo izejvielu pielietošanas un stikla šķiedras defektu izpēte

Material Science and Applied Chemistry ◽

10.7250/msac-2018-0007 ◽

2018 ◽

Vol 35 ◽

pp. 160-177

Author(s):

Janīna Sētiņa ◽

Gundars Mežinskis ◽

Vasilijs Akišins ◽

Laila Pētersone ◽

Inna Juhņeviča ◽

...

Keyword(s):

Glass Fibre ◽

Quartz Sand ◽

Raw Materials ◽

Glass Melts ◽

Mineral Raw Materials ◽

X Ray ◽

Experimental Glass ◽

Fibre Breakage ◽

Different Types ◽

Silicate Materials

Pētītas iespējas izmantot jaunas izejvielas stikla šķiedras ražošanā, īpašu uzmanību pievēršot Latvijas minerālām izejvielām – devona (Bāles atradne) un juras perioda (Skudras atradne un Pīlādžu atradne) kvarca smiltīm. Apstrādājot ūdenī Skudras atradnes kvarca smiltis, krāsojošo oksīdu daudzums samazināts līdz 0,066 %. Iegūto stiklu īpašību pārbaude parādīja attīrīto Skudru atradnes kvarca smilšu izmantošanas perspektīvu E-tipa stikla šķiedras ražošanā. Veikta arī citu šihtas izejvielu izpēte: kolemanīta, kianīta, kaļķakmens.Pielietojot augstas izšķiršanas spējas skenējošo elektronu mikroskopu, diagnosticēti stikla šķiedras defektu rašanās iemesli un izzināta to novēršanas iespēja.Study of Mineral Raw Materials and Defects in Glass FibresLatvian Devonian period sand from deposit Bāle and Jurassic period sand from deposit Skudra were studied, treated and compared with sand from existing Lithuanian supplier. Investigations of Latvian quartz sand showed that sand is characterized by surface impurities, which are easy to separate combining milling and water purification. These investigations and experimental glass melts using different types of sand confirmed that it is possible to use Latvian refined sand in glass industry.Other glass raw materials – colemanite, kyanite, kaolin, limestone – also have been examined.Glass fibre breakage points were studied using SEM, FTIR and X-Ray diffractions methods. Main reasons of glass fibre breakage are non-homogeneous glass and crystalline or gaseous inclusions coming from corrosion of refractory material. This article is result of the cooperation between Institute of Silicate Materials of Riga Technical University and JSC Valmieras stikla šķiedra.Keywords – glass, glass fibre, raw materials for glass, refined sand, glass defects

Download Full-text

Viral Inactivation with Emphasis on SARS-CoV-2 Using Physical and Chemical Disinfectants

The Scientific World JOURNAL ◽

10.1155/2021/9342748 ◽

2021 ◽

Vol 2021 ◽

pp. 1-6

Author(s):

Abdolmajid Fadaei

Keyword(s):

Sodium Hypochlorite ◽

Hepatitis Virus ◽

Virus Transmission ◽

World Health ◽

Health Concern ◽

Transmissible Gastroenteritis Virus ◽

Sodium Hypochlorite Solution ◽

Human Coronaviruses ◽

Tract Infections ◽

Physical And Chemical

Background. Recently, an outbreak of a novel human coronavirus SARS-CoV-2 has become a world health concern leading to severe respiratory tract infections in humans. Virus transmission occurs through person-to-person contact, respiratory droplets, and contaminated hands or surfaces. Accordingly, we aim at reviewing the literature on all information available about the persistence of coronaviruses, including human and animal coronaviruses, on inanimate surfaces and inactivation strategies with biocides employed for chemical and physical disinfection. Method. A comprehensive search was systematically conducted in main databases from 1998 to 2020 to identify various viral disinfectants associated with HCoV and methods for control and prevention of this newly emerged virus. Results. The analysis of 62 studies shows that human coronaviruses such as severe acute respiratory syndrome (SARS) coronavirus, Middle East respiratory syndrome (MERS) coronavirus or endemic human coronaviruses (HCoV), canine coronavirus (CCV), transmissible gastroenteritis virus (TGEV), and mouse hepatitis virus (MHV) can be efficiently inactivated by physical and chemical disinfectants at different concentrations (70, 80, 85, and 95%) of 2-propanol (70 and 80%) in less than or equal to 60 s and 0.5% hydrogen peroxide or 0.1% sodium hypochlorite within 1 minute. Additionally, glutaraldehyde (0.5–2%), formaldehyde (0.7–1%), and povidone-iodine (0.1–0.75%) could readily inactivate coronaviruses. Moreover, dry heat at 56°C, ultraviolet light dose of 0.2 to 140 J/cm2, and gamma irradiation could effectively inactivate coronavirus. The WHO recommends the use of 0.1% sodium hypochlorite solution or an ethanol-based disinfectant with an ethanol concentration between 62% and 71%. Conclusion. The results of the present study can help researchers, policymakers, health decision makers, and people perceive and take the correct measures to control and prevent further transmission of COVID-19. Prevention and decontamination will be the main ways to stop the ongoing outbreak of COVID-19.

Download Full-text

Investigation of the Physical and Chemical Characteristics of the Zeolites of the Kholinsky Deposit

Drug development & registration ◽

10.33380/2305-2066-2021-10-4-65-71 ◽

2021 ◽

Vol 10 (4) ◽

pp. 65-71

Author(s):

A. V. Bondarev ◽

E. T. Zhilyakova ◽

N. B. Demina ◽

K. K. Razmakhnin

Keyword(s):

Specific Surface ◽

Surface Area ◽

Raw Materials ◽

Molecular Model ◽

Three Dimensional ◽

Chemical Characteristics ◽

Structural Level ◽

Mineral Raw Materials ◽

Physical And Chemical ◽

Sorption Characteristics

Introduction. The mineral resource base of Russia has effective sorption substances that meet pharmaceutical requirements. Promising mineral raw materials are Zeolites, which combine the properties of an adsorbent and a "molecular sieve" due to the porous structure. In addition to the enterosorption direction, natural Zeolites are a source of macro-and microelements, which determines their use as biologically active food additives.Aim. Study of the physical and chemical characteristics of the Zeolites of the Kholinsky deposit.Materials and methods. The zeolite mineral raw materials of the Kholinsky deposit were used as objects of research. Optical microscopy was performed using a Leica DM direct microscope (Microsystems, Germany). Energy dispersion analysis was performed using an electron scanning microscope JSM-5300 (Jeol Ltd, Japan). The sorption characteristics were studied using the ASAP 2400 device (Micromeritics, USA) according to the method. The construction of a virtual three-dimensional molecular model of the Zeolite was carried out using the program Java Applet Jmol.Results and discussion. The physicochemical properties of Zeolites are investigated. It is established that morphologically the particles of the zeolite phase have a size of 5-30 microns, they are evenly distributed over the entire area of the site and represent the first structural level. Particles of the zeolite phase with a size of 5-6 microns form the second structural level due to Clinoptilolite crystals, microcracks and microgeodes. Based on the energy-dispersion spectral analysis, an increased content of the elements K, Na was revealed, which indicates the alkaline composition of the cation exchange complex. The studied Zeolite samples have micropores (volume 0.0031 cm3/g), mesopores (volume 0.0675 cm3/g), and a specific surface area of 29.1840 m2/g. A virtual three-dimensional molecular model of the Zeolite of the Kholinsky deposit has been developed. According to the molecular model, the sorption characteristics of the Kholinsky deposit Zeolite were: specific surface area - 1096.31 m2/g (1916.34 m2/cm3), the average diameter of the spherical molecule for adsorption in the pores is 5.97 A.Conclusion. The analysis of the sorption characteristics of the Zeolite revealed the following features: the pores occupy half the volume of the entire Zeolite, which are available for the sorption of water and low-molecular substances. Each pore in three mutually perpendicular directions communicates with the neighboring ones through "windows". A system of intracrystalline pores and cavities is formed, in which the occlusion and adsorption of molecules of the appropriate size easily occurs.

Download Full-text

Study on Manufacture of Short Mullite Fibers by Andalusite Mineral of Mei County China

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.99-100.1361 ◽

2011 ◽

Vol 99-100 ◽

pp. 1361-1364

Author(s):

Zhen Wu Shi ◽

Nian Suo Xie

Keyword(s):

Raw Materials ◽

Short Fiber ◽

Sintering Process ◽

Mineral Raw Materials ◽

X Ray ◽

Mullite Phase ◽

Mullite Fiber ◽

Mullite Fibers ◽

Sintered Temperature ◽

Electronic Microscope

The short mullite fibers were manufactured by andalusite mineral raw materials of Mei County China through isothermal sintering process between 1350°C and 1550°C under the oxidation atmosphere. And then the process which andalusite mineral raw materials of Mei County China had transformed into short mullite fibers was analyzed by X-ray automatic powder diffractometer D/MAX-2400, and the property of morphology of short mullite fibers was observed by scanning electronic microscope QUNATA200. The result manifests that in the range of experimental temperature, andalusite mineral raw materials of Mei County China fully transforms into mullite phase after the specimen is kept warm for 3 hours under sintered temperature 1450°C, and the mullite phases which are transformed at sintered temperature 1450°C mostly present in the form of short fiber while the temperature naturally cools to room temperature with furnace, and this kind of short mullite fiber has the best crystallinity, and the least structural defect and the highest length to diameter ratio.

Download Full-text

Purification of Oil-Containing Waste Using Solar Energy

Environmental and Climate Technologies ◽

10.2478/rtuect-2021-0011 ◽

2021 ◽

Vol 25 (1) ◽

pp. 161-175

Author(s):

Мaral Abdibattayeva ◽

Kylyshbay Bissenov ◽

Zheniskul Zhubandykova ◽

Raigul Orynbassar ◽

Lyazzat Tastanova ◽

...

Keyword(s):

Solar Energy ◽

Raw Materials ◽

Treatment Method ◽

Environmental Issue ◽

Treatment Technology ◽

Purification Method ◽

Environmental Setting ◽

Chemical Studies ◽

Physical And Chemical ◽

Commercial Oil

Abstract Significant oil losses in oil-containing wastes and their adverse impact on the region environmental setting bring about the need to develop an oil-containing wastes treatment technology. To tackle this issue, the authors have set an aim of designing a helio device and creating an oil-containing wastes treatment method based on it to extract oil products. Considering a widespread in the composition and properties of potential oil sludge raw materials and their tendency for either formation of stable emulsions or phase separation, we have conducted in-depth modern physical and chemical studies and defined the need to develop a commercial oil-containing wastes purification method. We have designed the device, in which oil product hydrocarbons undergo thermal treatment using solar energy. Following oil-containing wastes purification using solar energy, the particulate load in soil does not exceed 6.65–6.79 % and the absolute molecular weight of hydrocarbons approaches that of bitumen. The developed oil-containing wastes purification method solves an important environmental issue of oil-containing wastes recycling, promotes recovery, and prevents degradation of natural complexes, and reduces soil and water pollution.

Download Full-text