Topic Review
Bayer Red Mud Comprehensive Utilization Status
Red mud is a highly alkaline solid waste discharged in the alumina production process. The comprehensive utilization of Bayer red mud is mainly divided into the following aspects. (1) Building materials include the use of red mud for the production of cement or concrete; road cornerstones or pavement materials in road construction; and geopolymers, ceramics, or composites. (2) Applications in the environmental field include the use of red mud to remove heavy metals and improve acidic soils. (3) Applications in the chemical industry include the use of red mud to produce dyes, catalysts, coagulants, or adsorbents. (4) Recovery of valuable components from red mud includes recovery of alkali and extraction of elements, such as aluminum, iron, titanium, and scandium, and important metals, such as vanadium and gallium.
  • 292
  • 16 Jun 2023
Topic Review
Beneficiation of Rare Earth Elements
The rapid depletion of high-grade rare earth elements (REE) resources implies that future supplies may be augmented with low-grade ores, tailings, and other unconventional resources to meet cut-off grades and, subsequently, supply demands. There are distinct differences in the beneficiation response of REE and gangue minerals in the tailings. Gravity, wet magnetic, and froth flotation separation methods produced significantly varying REE recoveries and upgrades. Tabling presented a better potential for REE minerals upgrade compared to the Knelson Concentrator (KC). However, wet magnetic separation produced two REE “rich” preconcentrates. The two REE preconcentrates were subsequently upgraded via froth flotation. In terms of recovery, the best result was achieved during the multistage flotation process carried out on the tailings “feed” in the presence of hydroxamic acid and depressants. With high recoveries obtained using such readily available conventional separation methods, the tailings provide additional REE value to the primary commodities.
  • 705
  • 24 May 2022
Topic Review
Beta-Ti Alloys
β-Ti alloys are known for their excellent corrosion resistance, biocompatibility (in Ti-Nb alloys), and high strength-to-weight ratios, and some grades have a relatively low Young’s modulus (E). These favorable properties have led to the use of these alloys in the automotive, aerospace, biomedical, and industrial sectors.
  • 113
  • 01 Feb 2024
Topic Review
Biobeneficiation of PGMs
Conventional beneficiation of the Platinum Group of Metals (PGMs) relies on the use of inorganic chemicals. With the depreciation of high grade deposits, these conventional processes are becoming less economically viable. Furthermore, the use of chemicals has serious negative impacts on the environment. To address the challenges of conventional PGM beneficiation, biobeneficiation has been proposed. Bio-beneficiation is the concentration of mineral species by employing microorganisms that interact with either the gangue or the valuable mineral species. Bio-beneficiation can also be described as the use of microorganisms to interact with minerals to subsequently induce processes such as magnetic separation, flotation, and flocculation.
  • 904
  • 19 Jan 2022
Topic Review
Biorecovery of Critical Raw Materials through Archaeal factory
Bio-metallurgy is a promising alternative for e-waste valorisation based on biological routes of specialised microorganisms able to leach solid-containing metals. Because of the physiology of these microorganisms, microbial leaching can be economically feasible, besides being an environmentally sustainable process. Like Bacteria and Fungi, Archaea are also capable of metal leaching activity, though their potential is underestimated. Because of the physiology of these microorganisms, microbial leaching can be both economically and environmentally sustainable. Archaea, Bacteria and Fungi, are capable of metal leaching activity, although their potential is underappreciated.
  • 253
  • 04 May 2023
Topic Review
Cadmium Recovery from Spent Ni-Cd Batteries
The significant increase in the demand for efficient electric energy storage during the last decade has promoted an increase in the production and use of Cd-containing batteries. On the one hand, the amount of toxic Cd-containing used batteries is growing, while on the other hand, Cd is on a list of critical raw materials (for Europe). Both of these factors call for the development of effective technology for Cd recovery from spent batteries. Alkaline nickel-cadmium (Ni-Cd) batteries are widely used as autonomous sources of industrial and household current (power banks) due to a successful combination of feasibility studies and achieved sustainable electrical characteristics. In recent decades, the market of secondary current sources for portable equipment has undergone significant changes, which leads to an intensive replacement of Ni-Cd batteries with lithium-ion (LIB) and nickel-metal-hydride.
  • 636
  • 07 Feb 2022
Topic Review
Carbon Nanotubes-Based Nano Materials
High modulus of about 1 TPa, high thermal conductivity of over 3000 W/mK, very low coefficient of thermal expansion (CTE), high electrical conductivity, self-lubricating characteristics and low density have made carbon nanotubes (CNTs) one of the best reinforcing materials of nano composites for advanced structural, industrial, high strength and wear-prone applications. This is so because it has the capacity of improving the mechanical, tribological, electrical, thermal and physical properties of nanocomposites.
  • 401
  • 01 Mar 2023
Topic Review
Chemical and Physical Properties of Solid Salt Fluxes
Solid salt fluxes are inorganic compounds that are added during the treatment of molten aluminum to improve the final quality. An understanding of the chemical composition of the flux is essential for the assessment of the physical and chemical behavior of the flux. The chemical composition of the flux can be tailored to adjust properties such as density, viscosity, reactivity, and wettability. Such properties, in turn, will impart different functions to the flux. 
  • 764
  • 05 May 2023
Topic Review
China Intelligent Manufacturing Technology in the Steel Industry
Intelligent manufacturing, defined as the integration of manufacturing with modern information technologies such as 5G, digitalization, networking, and intelligence, has grown in popularity as a means of boosting the productivity, intelligence, and flexibility of traditional manufacturing processes. The steel industry is a necessary support for modern life and economic development, and the Chinese steel industry’s capacity has expanded to roughly half of global production.
  • 1.1K
  • 03 Nov 2022
Topic Review
Chloride-Induced Corrosion of Carbon Steel in Cracked Concrete
Corrosion is an electrochemical reaction consisting of anodic and cathodic half-cell reactions. Micro-cell corrosion refers to the situation where active dissolution and the corresponding cathodic half-cell reaction occur in adjacent parts of the same metal. For a steel reinforcing bar in concrete, the surface of the corroding steel can act as a mixed electrode containing both anode and cathode regions connected by the bar itself. Macro-cell corrosion can also form on a single bar exposed to different environments within the concrete or where part of the bar extends outside the concrete. In both cases, the concrete pore solution functions as an electrolyte.
  • 428
  • 16 Jun 2022
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