Utilization of Secondary Copper Smelting Slags for Proppant Production

Selective leaching of base metals from copper smelter slag

Although ammonia leaching of copper from slags has been reported generally as a part of copper slag utilization methods, but no detailed studies have been reported in the literature. In this research, we tried to investigate the effect of different parameters on ammonia leaching of copper from copper smelting slag by identifying different copper-bearing phases and following them during leaching time. Mineralogical characterization of the smelting slag (1.7 pct Cu) was done using X-ray fluorescence, X-ray diffraction, optical microscopy, diagnostic leaching tests, and scanning electron microscopy. The characterization studies indicated that main copper-bearing species are soluble copper oxides and chalcocite along with minor amount of covellite, bornite, blister copper particles, and chalcopyrite. It was also found that only approximately 0.2 pct Cu was present in the insoluble bulk silicate phases. These results suggest that approximately 88 pct of the total copper of slag could be extracted by ammonia sulfide leaching. Leaching tests were carried out and the effects of various parameters, namely pH, ammonia concentration, temperature, presence of oxygen, stirring speed, and pulp density were examined on copper leaching. The temperature and stirring speed had the most pronounced effect on the copper leaching, whereas ammonia affected the leaching yield at low concentrations of ammonia. It was found that 78 pct of Cu could be extracted within 4 hours and under optimum conditions: T = 343 K (70 °C), 2M ammonia, pH 10.5, stirring speed = 900 rpm, pulp density = 10 pct (ws/v). The kinetic data were analyzed with the shrinking core models, and it was found that the leaching process is controlled by both the interfacial transfer and diffusion across the product layer and the activation energy is calculated to be 49.4 kJ mol−1.

Utilization of industrial waste is of utmost important due to pollution constraints. Large quantities of converter and anode slags are generated in different unit operations for the production of copper in I.C.C. Ghatshila. The converter slag contains about 2.75% copper, 0.9% nickel, 52.0% iron, and 0.6% cobalt and cannot be rejected due to its economic importance. X-ray diffraction (XRD) studies revealed the presence of copper in elemental, oxide, and silicate phases and iron in silicate (feyalite) and oxide (Fe2O3) phases. From the earlier work on leaching by an acetic acid lixiviant up to 55% Copper could be extracted at 250 mL of acetic acid/100 g of slag, 125 °C temperature, and 35 atm of oxygen pressure. Low copper recovery was attributed to the presence of copper silicate and sulfide phases which could not be detected by XRD. Therefore, reduction roasting by noncoking coal was done to increase the copper recovery. A coal sample from Talchar which contained 30% fixed carbon, 40% volatile, and 30% ash was used for reduction roasting. Pellets were prepared manually by mixing powdered coal in different proportions with ground slag (−100 mesh). Roasting of the pellets was carried out in the temperature range of 650−800 °C. Maximum percent extraction of copper and nickel (97% Cu and 20% Ni) could be achieved at the temperature of 720 °C for 90 min of roasting with 20% reductant. The acetic acid requirement was 130 mL/100 g of reduced pellets, while leaching at the oxygen pressure of 35 atm for 120 min at 120 °C. The solid−liquid ratio was maintained at 1:5 in all the experiments. The copper concentration in the leach liquor was 4.5 g/L. Iron dissolution was minimum (max 1%) in all the experiments. The ion-exchange technique was employed to separate copper from acetate solution. Zeolite resin was found to be suitable for the separation of copper from leach liquor. About 92% copper was recovered by geolite. 2.5 N H2SO4 was found to be most effective for the stripping of the copper from resin.

Rheological behavior of heated starch dispersions: Role of starch granule

To achieve optimal mechanical properties in high manganese steels, the precipitation of nanoprecipitates of vanadium and niobium carbides is under investigation. It is shown that under controlled heat treatments between 850°C and 950°C following hot deformation, few-nanometre precipitates of either carbide can be produced in test steels with suitable contents of vanadium or niobium. The structure and chemistry of these precipitates are examined in detail with a spatial resolution down to better than 1 nm using a newly commissioned scanning transmission electron microscope. In particular, it is shown that the nucleation of vanadium carbide precipitates often occurs at pre-existing titanium carbide precipitates which formed from titanium impurities in the bulk steel. This work will also highlight the links between the nanocharacterisation and changes in the bulk properties on annealing.

Agricultural crop residues, such as straw, corn stover and wood wastes such as leftovers from timber cutting, broken furniture, sawdust, residues from paper mills etc. contain appreciable quantities of cellulose, hemicelluloses and lignin. Much effort has been devoted to convert these types of biomass into useful industrial and commercially viable products. During liquefaction, lignocellulosic components are depolymerised to low molecular mass compounds with high reactivity and high hydroxyl group content. We have used a high energy ultrasound as an energy source to speed up the liquefaction process in our research. The liquefied biomass was used as a f eedstock in synthesis of polyesters, polyurethane foams and adhesives. Adhesives for the wood particle boards with incorporated liquefied lignocellulosic materials emit less formaldehyde and products have the same or even better mechanical and physical properties. A special attention was given to the utilization of the liquefied lignocellulosic materials as a new energy source with high heating value. It was found that the combustion efficiency of lignocellulosic liquid fuel is comparable to the combustion efficiency of Diesel fuel although it has much higher content of cyclic hydrocarbons. The emissions are within the range of the European emission regulations. The utilization of liquefied lignocellulosic materials can at least partially reduce the crude oil consumption, thus increasing the use of the renewable resources in large extent.

Effects of sulfate on the mechanical performances and hydration characteristics of red mud based non-burnt brick

The use of oxygen, strontium and lead isotopes to provenance ancient glasses in the Middle East

Despite several literatures exist on out-grower scheme in many countries for both crops and animals, little or no study exist on the sugarcane out-grower scheme around communities surrounding the Sunti sugar plant owned by Golden Penny Company. The study investigated the efficacy of the outgrower scheme under the sugar policy in providing sugarcane raw material for sugar production by sugarcane outgrowers in Sunti local community of Mokwa in Niger state by examining how the sugarcane out-grower scheme serve as source of raw material to the Company the and the extent of the reliability of the scheme as source of raw material for Sunti Sugar Company. Questionnaire and interview schedule was utilised to collect data from staff of sugar plant in-charge of the scheme. Observation was used to study the habitat of outgrowers and get data on the scheme. Results shows that the scheme enhanced the timely availability of sugarcane supply according to the company specification; ensure price stability and cost effectiveness; comparatively more productive and fulfils government policy obligation on Backward Integration Measure within the sugar policy in Nigeria in the study area. Despite immense benefit the company derives from the scheme among other benefits, it falls short in terms of Corporate Social Responsibility. The company’s welfare activities towards surrounding communities are insignificant. Base on the findings of this research, it is recommended that deliberate measures on Corporate Social Responsibility such as “tax break for social amenities” by the NSDC should be effectively and efficiently enforced which takes into cognisance sugar company’s profitability and tax need of government. Yearly social amenities scorecard can be used by the NSDC to ensure compliance.

This study is intended to analyze the source of fresh fish and the quantity of fresh fish used in the business of making dried fish in Bengkulu City and analyze what factors affect the quantity of demand for fresh fish in the business of making dried fish in Bengkulu City. This research was conducted from January to February 2022 in Bengkulu City, more precisely, Sumber Jaya Village, Kampung Melayu District. The research location was determined purposively, and 86 dried fish makers were selected using the census method. The data used are primary and secondary, and the data analysis used is qualitative and quantitative. Sources of raw materials in dried fish are divided into three: self-catch, buy, and self-catch and buy. The largest percentage of sources of raw materials is to buy, where the place to get the most comes from fishermen directly. The quantity of raw material used is 10,563 Kg per production process. The factors that partially affect the quantity of demand for fresh fish by dried fish makers are the price of ice and the dummy of the business scale at the 95% confidence level.

. The scientific article presents the results of innovative technologies used in the anaerobic fermentation of biomass of green plants, as well as the cultivation of local enzymatic strains in elective conditions. At the same time, in the course of morphocytological experiments, the results of the description of lactic acid bacteria that carry out complete silage in the process of feed production are presented. The study of new and economically accessible sources of high-quality protein raw materials is an urgent problem in modern agricultural biotechnology. One of the solutions to this problem is the use of microalgae as a source of bio-feed. In a number of countries, single-celled algae Clorella and Scenedesmus are used for the production of feed protein instead of traditional sources of raw materials, such as plant resources and the protein mass of microorganisms. Based on these data, it is obvious that in order to maintain the normal functioning of the body, timely cell renewal, and a constant synthesis of various forms of proteins, including essential amino acids, must be carried out. In this regard, many scientific laboratories in the field of agricultural biotechnology, including Kazakhstan, are intensively engaged in the problems of providing and increasing the content of feed preparations with essential amino acids. The article presents the results of scientific research on the microbiological identification of microalgae living in the rivers of the Turkestan region. In the course of the research work, the taxonomic identification of local microalgae strains was carried out, as well as their morphological features were studied. In addition, natural populations were cultured on elective media under laboratory conditions.

In recent years the studying of the raw materials economy has gained importance and aims to show the human behavior and life style of the people lived in the past, hunting strategies, and settlement systems. Thus, in this study, the stone tools were recovered from Hatay Province of the Middle Paleolithic period caves: Ucagizli II, Merdivenli, and Tikali, examined to understand raw material economies. In this context, it is determined to reveal inhabitants of those caves settlements, what kind of sources of raw materials used in the past and how they manage these resources in behavioral traits. As a result of excavations and surveys conducted in the region have been identified two types of source of raw materials. These resources are defined as the primary and secondary by the geological formations. According to the geological formations in the caves shelled flint pebbles, which are often used in the secondary. The primary sources of raw materials consumed less frequently.

Sustainable utilization of agro-industrial waste has been established as a key strategy for addressing environmental and economic challenges. This study focused on identifying how agro-industrial waste from fruits and vegetables is utilized globally. To achieve this, the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) method was employed, which facilitates the conduct of systematic reviews and meta-analyses. This approach allows for a comprehensive and structured literature search, ensuring transparency and reproducibility in the review process. The study's results revealed that 29.9% of the waste is optimized through fermentation processes, while 16% is utilized via supercritical fluid extraction (SFE). These findings conclude that sustainable utilization of agro-industrial waste, through innovative methods such as fermentation and supercritical fluid extraction, provides effective solutions to environmental and economic challenges. These methods not only enable the conversion of waste into high-value products but also contribute to waste reduction and the promotion of a circular economy, aligning with global goals of waste reduction and resource optimization.

Multiscale investigations were conducted to explore the hydration phases development of magnesium phosphate cement (MPC) incorporating supplementary cementitious materials (SCMs) such as pulverized fuel ash (PFA), limestone powder (LS), and calcined clay (CC). Strength, reaction products, chemical structures of hydration phases, and microstructures were analyzed using advanced material characterization techniques, including QXRD, SEM, TGA, FTIR, BSE-EDS, micro-Raman spectroscopy, NMR, and nanoindentation. The primary MPC hydration product, struvite, along with secondary reaction products, such as M-S-H, C-S-H, and C-A-S-H were identified to understand the development of calcium silicate and aluminosilicate phases in the MPC pastes blended with three SCMs. Moreover, MPC specimens containing 25% SCMs combining PFA, LS, and CC exhibited the 19.6% higher compressive strength at 28d as compared to the samples having only 10% PFA. . Adding the SCMs into the MPC mixes led to the refined microstructures through the formation of intermediate and amorphous phases.

The function of regenerators is to use the thermal energy of the waste gases to preheat the combustion air and thereby provide better heat transfer via a high flame temperature. Satisfactory furnace operation can only be achieved if the regenerator chambers are in good condition. Today, environmental issues play a major role in the selection of regenerators and checkers refractories. The impact on the environment has been studied on 35 side-fired flat glass furnaces. Firstly, we will describe in this paper the issues raised by increased carry over and CO content observed in various furnaces with different types of checker packing such as basket weaves, box blocks and cruciforms . Secondly, we will talk about how the impact on health and waste/recycling solutions is analyzed and should be taken into consideration before ordering refractories. Finally, some new materials are now appearing on the market. The fact that China dominates magnesia production (51% of the world production) entails the rise of new raw material sources for the basic refractories used for checker bricks. Besides that, the refractories suppliers are continuously improving their materials to offer glassmakers new solutions to overcome the actual issues in the regenerators. These new sources of materials have been analyzed in R&D and are now considered as potential solutions which need further testing under industrial conditions.