Description:
Mechanical activation of materials, including minerals, has been an area of increasing interest in the past twenty years due to the unusual effects that can be obtained by extended milling. One apparent flaw in much of the research is the use of activation devices which are not available at the scale required for industrialization of production. A review of the effects of activation is made and a critical assessment of the key requirements for commercialization of MA processes is made.
Description:
Mechanical activation of materials, including minerals, has been an area of increasing interest in the past twenty years due to the unusual effects that can be obtained by extended milling. One apparent flaw in much of the research is the use of activation devices which are not available at the scale required for industrialization of production. A review of the effects of activation is made and a critical assessment of the key requirements for commercialization of MA processes is made.
Description:
The effect of dry milling on the carbothermic reduction of celestite was investigated. Mixtures of celestite concentrate (98% SrSO4) and activated carbon (99% carbon) was milled for 1 and 24 hours in a planetary ball mill. Un-milled and milled mixtures and their products after carbothermic reduction were studied by a combination of XRD and TGA/DTA experiments. The thermogravimetric analyses and XRD results showed that by milling celestite-carbon mixtures for one hour, the formation temperature of strontium sulfide decreased from about 720°C (in un-milled sample) to about 600°C, after 24 hours milling it decreased to 530°C. It was concluded that milling induces increasingly thorough mixing of the reactants to reduction occurring at lower temperatures.