Design of Reduction Process of SnO2 by CH4 for Efficient Sn Recovery

A green method to synthesize spherical Sn particles by reducing SnO2 film in atmospheric-pressure H2/Ar plasma at low temperatures for various applications is presented. The floating wire-assisted remotely-generated plasma with a mixture of 0.05% H2/Ar gas formed spherical metallic Sn particles by reducing a SnO2 layer on glass substrate. During the reduction process, H radical density was measured by using vacuum ultraviolet absorption spectroscopy, and plasma properties including electron density and gas temperature were diagnosed by optical emission spectroscopy. The inductively coupled generated plasma with a high electron density of 1014 cm−3, a hydrogen atom density of 1014 cm−3, and a gas temperature of 940 K was obtained at a remote region distance of 150 mm where the SnO2/glass substrate was placed for plasma treatment. The process has been modeled on the spherical Sn formation based on the reduction of SnO2 films using H radicals. Depending on the treatment condition, the total reduction area, where spherical Sn particles formed, was enlarged and could reach 300 mm2 after 2 min. The substrate temperature affected the expansion rate of the total reduction area and the growth of the Sn spheres.

Section: Formation Of Spherical Sn Particles By Reducing Sno 2 Film Imentioning

confidence: 99%

Formation of spherical Sn particles by reducing SnO2 film in floating wire-assisted H2/Ar plasma at atmospheric pressure

Nguyen

Sasaki

Tsutsumi

et al. 2020

“…However, series of natural minerals and slags were commonly used to prepare composite phase change materials (C-PCMs) for thermal energy storage, which provided new insights to utilize metallurgical slags through environment-friendly and high-value-added processes 19–22 . Natural clay minerals (kaolin, diatomite, sepiolite, bentonite, perlite, etc) have porous structure and considerable specific surface area, thus, those minerals were always with excellent adsorbability and suitable for preparing low-temperature C-PCMs (~100 °C) 23–26 . Industrial solid wastes such as fly ash (FA) and blast furnace slags (BFS) were obtained from high-temperature processes, which showed excellent thermostability and corrosion resistibility.…”

Section: Introductionmentioning

confidence: 99%

A value-added multistage utilization process for the gradient-recovery tin, iron and preparing composite phase change materials (C-PCMs) from tailings

Chen

et al. 2019

Tin-, iron-bearing tailing is a typically hazardous solid waste in China, which contains plenty of valuable tin, iron elements and is not utilized effectively. In this study, a multistage utilization process was put forward to get the utmost out of the valuable elements (tin and iron) from the tailings, and a gradient-recovery method with three procedures was demonstrated: (1) An activated roasting followed by magnetic separation process was conducted under CO-CO2 atmosphere, tin and iron were efficiently separated during magnetic separation process, and 90.8 wt% iron was enriched in magnetic materials while tin entered into non-magnetic materials; (2) The tin-enriched non-magnetic materials were briquetted with CaCl2 and anthracite and roasted, then tin-rich dusts were collected during the chloridizing roasting process; (3) The roasted briquettes were infiltrated in melting NaNO3 to prepare NaNO3/C-PCMs by a infiltration method. Three kinds of products were obtained from the tailings by the novel process: magnetic concentrates containing 64.53 wt.% TFe, tin-rich dusts containg 52.4 wt.% TSn and NaNO3/C-PCMs for high temperature heat storage. Such a comprehensive and clean utilization method for tin-, iron-bearing tailings produced no secondary hazardous solid wastes, and had great potential for practical application.

“…In our previous report 20,21 , we have designed a methane reduction (MR) method, an ecofriendly and simple versatile process of Sn recovery from SnO x containing industrial wastes, which also can be potentially applied for Sn ore smelting. A direct facile contact between gas phase methane and SnO x improves the efficiency of the reaction.…”

Section: Introductionmentioning

confidence: 99%

“…A direct facile contact between gas phase methane and SnO x improves the efficiency of the reaction. Moreover, multiple reductants provided by methane (hydrogen and carbon) sequentially reduce SnO x , producing H 2 O, H 2 , CO, or CO 2 depending on the reduction conditions 21 . The geometry of a SnO 2 bound methane inhibits the initial participation of the carbon of methane to the reduction process 21 .…”

Section: Introductionmentioning

confidence: 99%

Efficient Sn Recovery from SnO2 by Alkane (CxHy=2x+2, 0 ≤ x ≤ 4) Reduction

Yoo

et al. 2019

Self Cite

We study the mechanism of alkane reduction of SnO2 for efficient low-temperature recovery of Sn from SnO2. Based on thermodynamic simulation results, we comparatively analyze the reduction behavior and the efficiency of SnO2 reduction by H2 and alkanes (CxHy=2x+2, 0 ≤ x ≤ 4). We found that alkanes (n·CxHy) with the higher nx generally complete the reduction of SnO2 (T100) at the lower temperature. Moreover, the T100 of the SnO2 reduction by alkanes (n·CxHy) was decreased from the T100 of pure hydrogen with the same amount of hydrogen atoms (n·Hy). We found that the concentration of a gas phase product mixture, the amount of the produced solid carbon, and the T100 complementary vary as a function of the nx and ny, the total amount of carbon and hydrogen atoms in the reducing gas phase molecules. Our results demonstrate a viability of the low temperature reduction method of SnO2 by alkanes for efficient recovery of Sn from SnO2, which can be applied for Sn recovery from Sn containing industrial wastes or Sn ores with economic value added that is held by the co-produced H2.