Preconcentration of gold by rice husk ash

doi:10.1016/S0892-6875(00)00021-2

Minerals Engineering

Volume 13, Issue 4, April 2000, Pages 391-400

https://doi.org/10.1016/S0892-6875(00)00021-2 Get rights and content

Abstract

The goal of this research was to develop a new, efficient adsorbent of gold-thiourea complex, [Au(CS(NH₂)₂]⁺. In this experiment, rice husk was heated at three different temperature: 300°C, 400°C and 500°C. Rice husk ash heated at 300°C adsorbed gold thiourea complex, whereas rice husk ash heated at 400°C and 500°C did not. The structure of rice husk ash heated at 300°C had specific silanol groups and oxygen functional groups of carbon, while rice husk ash heated at 400°C and 500°C contained siloxane groups. Maximum gold adsorption of rice husk ash heated at 300°C and activated carbon, was 21.12 and 33.27 mg Au/g adsorbent, respectively. However, rice husk ash absorbed 0.072 mg thiourea/g adsorbent, which was less than activated carbon adsorbed (0.377 mg thiourea/g adsorbent). In addition, the adsorbed gold could be eluted from this rice husk ash by sodiumthiosulfate more easily than from activated carbon. The results revealed that rice husk ash heated at 300°C can be used as a new adsorbent for gold thiourea complex.

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^☆: Presented at Minerals Engineering '99, Falmouth, Cornwall, England, September 1999

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Preconcentration of gold by rice husk ash☆

Abstract

Inorganica Chimica Acta

Cement and Concrete Research

Hydromettalurgy

Minerals Engineering

Cement and Concrete Research

Cement and Concrete research

Canadian Metallurgical Ouarterly

Canadian Metallurical Quarter

Hydrometallurgy

Minerals Engineering

Minerals Engineering

The determination of pore volume and area distributions in porous substances. I. Computations from Nitrogen Isotherms

Journal of the American Chemical Society

Rice-husk convension to energy

Fabric and mineral analysis of soils