Abstract: It is anticipated that laser cladding assisted with preheat (LCAP)-deposited Tribaloy (T-800) composite coatings enhances resistance to structural degradation upon exposure to elevated-temperature oxidation service environments. The oxidation kinetics of LCAP T-800 composite coatings deposited on EN8 substrate and its mechanisms have not been explored in severe conditions that are similar to operational parameters. The isothermal oxidation behaviour of the T-800 composite coating d...
Abstract: Before disposal of any metallurgical waste to the environment, it is the responsibility of mining institutes to adhere to the permissible metal content limits. Base metals, especially iron and copper, have adverse effects of reducing the soil pH and excessive concentrations of these in the disposed waste may result in soil pollution and toxicity, with adverse effects on plant growth and animal health. Copper slag is a metallurgical waste that is disposed by way of stockpiling at de...
Abstract: Surface structure determines the performance of materials in service. Enhancing the surface topography of materials with a refractory ceramic coating such as Titanium carbide has gained unprecedented development of recent due to the increase in applications of these functionally graded materials. Radio frequency (RF) magnetron sputtering exhibits a lot of potential in depositing and growing thin film thin. One of the major advantages of RF magnetron sputtering is the ability to be ...
Abstract: In this article, alternative forms of optimizing the milling efficiency of a laboratory scale ball mill by varying the grinding media size distribution and the feed material particle size distribution were investigated. Silica ore was used as the test material. The experimental parameters that were kept constant in this investigation was the grinding media filling, powder filling and the mill rotational speed. The data obtained from these batch tests was then analyzed using a model...
Abstract: This study investigated the application of the attainable region optimization technique to establish the optimum hybrid hydrometallurgical and pyro-metallurgical process conditions required to treat the electric arc furnace dust. The analysis of the results obtained showed that a combination of an agitation speed of 800 rpm, sodium hydroxide concentration of 8.0 mol/L and a leaching temperature of 80 °C were the optimum conditions for the hydrometallurgical process, while a ...
Abstract: Currently the majority of the world’s steel is produced through either one of the two main routes; the integrated Blast Furnace – Basic Oxygen Furnace (BF – BOF) route or the Direct Reduced Iron - Electric Arc Furnace (DRI - EAF) route. In the former, the blast furnace uses iron ore, scrap metal, coke and pulverized coal as raw materials to produce hot metal for conversion in the BOF. Although it is still the prevalent process, blast furnace hot metal production has declined ...
Abstract: amibia Custom Smelters (NCS) process a range of copper concentrates in their three furnaces, namely; top submerged lance, copper converter and reverberatory furnaces, in order to produce mattes and fayalitic slags. The copper content of the slags range between 0.8 to 5 wt. % and this is considered too high for disposal to the environment. Currently, the slags are sent to a milling and flotation plant for liberation and recovery of residual copper. The copper recoveries realized in ...
Abstract: The effect of ZrB2-Si3N4 particle reinforcement on the tribological behavior and microstructure of AA8011 alloy has been studied. ZrB2-Si3N4 particles were varied from 0 wt% to 20 wt% with an interval of 5 wt%. Dry sliding pin-on-disc tests at a room temperature condition were conducted to investigate the wear performances of the aluminium alloy/ ZrB2-Si3N4 composites. The tests were conducted at varying loads, from 20 to 40 N. The results depicted that the wear rates of th...
Abstract: Control and manipulation of synthesis parameters of thin film coatings is of critical concern in determination of material properties and performance. Structural and morphological properties of rf-sputtered WC-Co thin films deposited under varying deposition parameters namely, substrate temperature and rf power are presented in this data article. The surface morphology, crystallite size and nature were acquired using x-ray photoelectron spectroscopy (XPS) and Grazing Incidence X-ra...
Abstract: Copper slag is a hard material produced from smelting copper-bearing ores. Over the years, research has prioritized utilizing slag as a secondary source of base metals. This paper focuses on the grinding/milling of copper slag collected from the BCL Mine in Botswana to obtain a maximum amount of material in the desired size class with minimal energy consumption. This will then be followed by an integrated flotation and leaching approach of the desired size class material to recover...
Abstract: Copper slag is generated when copper and nickel ores are recovered from their parent ores using a pyrometallurgical process, and these ores usually contain other elements which include iron, cobalt, silica, and alumina. Slag is a major problem in the metallurgical industries as it is dumped into heaps which have accumulated into millions of tons over the years. Moreover, they pose a danger to the environment as they occupy vacant land (space problems). Over the past few years, stud...
Abstract: In this article, we investigate the effect of micro-organisms on the rate of corrosion of stainless steel and mild steel alloys. The three analytical techniques we will employ in measuring the rate of corrosion are the electrochemical impedance spectroscopy, cyclic polarization and the mass loss method. The test material used is the 316L stainless steel and the mild steel coupons. The microorganism we are going to use for this investigation is the sulphate-reducing bacteria (SRB). ...
Abstract: In this study, bimetallic nanofiller capable of usage as reinforcement was synthesized from expanded polystyrene (EPS). Bimetallic materials consist of two different metals. The bimetallic nanofiller consisting of SrO and K2O was successfully developed by the hydrothermal method which many researchers have well utilized to prepare nanoparticles in recent times. This study aims to synthesize and characterize bimetallic SrO-K2O, nanofillers from recycled expanded polystyrene (EPS). P...
Abstract: In this paper, the preparation and characterization of ZnO nanofillers from polystyrene (PS) polymer waste for use as reinforcement was presented. This was done to achieve a better means of upcycling polymer wastes that have become social menace in recent times. The PS/ZnO nanofillers was synthesized through the hydrothermal synthesis of nanocomposites in an enclosed reactor. The reactor was kept in an oven at a specified temperature for a period. A product obtained was characteriz...
Abstract: An investigation was carried out to evaluate the isothermal oxidation behavior of nickel based superalloys at 1100 °C for 120 h. The alloys which were microstructured and nanostructured were developed by spark plasma sintering system. The oxidation test was carried out at a temperature of 1100 °C in air at different exposure time up to 120 h. The nanostructured nickel based alloy possessed better oxidation resistance with the formation of continuous adherent alumina, chro...