Synthesis of Carbide Ceramics via Reduction of Adsorbed Anions on an Activated Carbon Matrix

Wallace, Grant C.; Downey, Jerome P.; Chorney, Jannette; Mallard, Alaina; Hutchins, David L.

doi:10.1007/978-3-319-51340-9_6

Cited by 5 publications

(5 citation statements)

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“…Previous studies have shown that the maximum required temperature for synthesizing micron-sized WC particles from anion-loaded precursors is significantly lower than that used in the conventional WC synthesis 7 The maximum temperature required to produce WC particles in the former technique is 850 °C, while the average temperature for the production of WC in the latter technique is around 1500 °C. 7 It is worth noting that the WC particles produced in the conventional technique are significantly coarser than those produced by the adsorption of tungstate oxyanions on an activated carbon substrate. The average size of WC particles produced by the adsorption of tungstate oxyanions on activated carbon substrates is around 2 μm.…”

Section: ■ Introductionmentioning

confidence: 96%

“…A less time and energy-intensive process for producing ultrafine tungsten carbide particles is under development at Montana Technological University. Research has proved that highly uniform ultrafine tungsten carbide particles can be produced in a process sequence that entails the adsorption of tungstate anions on an activated carbon (AC) substrate followed by reduction and carburization at elevated temperature under a controlled gas atmosphere . The process steps are amenable to continuous mode operation, and the temperature required for reduction and carburization steps is substantially lower than that currently employed in industrial practice.…”

Section: Introductionmentioning

confidence: 99%

“…Research has proved that highly uniform ultrafine tungsten carbide particles can be produced in a process sequence that entails the adsorption of tungstate anions on an activated carbon (AC) substrate followed by reduction and carburization at elevated temperature under a controlled gas atmosphere. 7 The process steps are amenable to continuous mode operation, and the temperature required for reduction and carburization steps is substantially lower than that currently employed in industrial practice. Previous studies have shown that the maximum required temperature for synthesizing micron-sized WC particles from anion-loaded precursors is significantly lower than that used in the conventional WC synthesis 7 The maximum temperature required to produce WC particles in the former technique is 850 °C, while the average temperature for the production of WC in the latter technique is around 1500 °C.…”

Section: ■ Introductionmentioning

confidence: 99%

“…7 The process steps are amenable to continuous mode operation, and the temperature required for reduction and carburization steps is substantially lower than that currently employed in industrial practice. Previous studies have shown that the maximum required temperature for synthesizing micron-sized WC particles from anion-loaded precursors is significantly lower than that used in the conventional WC synthesis 7 The maximum temperature required to produce WC particles in the former technique is 850 °C, while the average temperature for the production of WC in the latter technique is around 1500 °C. 7 It is worth noting that the WC particles produced in the conventional technique are significantly coarser than those produced by the adsorption of tungstate oxyanions on an activated carbon substrate.…”

Section: ■ Introductionmentioning

confidence: 99%

“…The size of WC particles produced by the adsorption of tungstate oxyanions on the activated carbon substrate is well within most industries' desired range, but the carbide particles produced in the aforementioned technique remain bonded to the carbon substrate, as shown in Figure 1. Since it has been previously established that the production of micron-sized WC particles by the adsorption of tungstate oxyanions on an activated carbon substrate was significantly more energyefficient than that of the conventional techniques, 7 therefore, the research described in this paper only identifies a method for liberating and separating the carbide particles from the carbon substrate without significantly altering their size and shape. The particles were first ball-milled for 6 h for liberation purposes only, and to achieve full separation, the particles were then centrifuged with lithium metatungstate (LMT) followed by two rounds of centrifugation with sulfuric acid.…”

Section: ■ Introductionmentioning

confidence: 99%

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Liberation and Separation of Ultrafine Tungsten Carbide Particles from an Activated Carbon Substrate

Davis

Downey

2022

ACS Sustainable Chem. Eng.

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Production of fine-grained tungsten carbide is expensive due to the energy-intensive techniques employed in traditional commercial operations. Recent research has shown that ultrafine (<2 μm) tungsten carbide particles can be produced by the adsorption of tungstate oxyanions on an activated carbon substrate followed by reduction and carburization at elevated temperature under a controlled furnace atmosphere. The thermal processing step is effective at temperatures substantially lower than those used in commercial practice. However, the carbide particles remain bonded to the surfaces of the larger carbon particles. Liberation and separation of the carbide particles have proved challenging, and the literature suggests that comminution and classification at this scale have not been thoroughly investigated. This paper describes the development of a highly effective method for liberation, separation, and purification of ultrafine tungsten carbide particles. It is paramount to note that to maintain the energy efficiency of the technique and to avoid any unwanted changes to size and shape and also to avoid the agglomeration of WC particles due to heat, any techniques that could have introduced a significant amount of heat during liberation and separation of WC particles had to be avoided. This resulted in the elimination of techniques such as burning off the activated carbon substrate or any exothermic chemical reactions, which posed another significant challenge on the liberation and separation of WC particles. Taken together, physical liberation (ball milling) and separation (centrifugation) were proved to be highly effective to achieve the aforementioned goals.

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Section: ■ Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%