Abstract: A process for producing caustic calcined magnesia (CCM) includes calcining a magnesium containing material, such as magnesite, in a primary calciner to produce a primary calcined material and a primary exhaust comprising dust; subjecting the primary exhaust to separation to recover a dust material includes incompletely calcined dust particles; calcining the dust material in the secondary calciner to produce calcined dust, wherein the dust material is not co-calcined with the magnesium containing material or the primary calcined material. The primary calcined material and the calcined dues thus form two CCM products, which can be kept separate or combined. The primary calciner can be a multiple hearth furnace (MHF) while the secondary calciner can be a gas suspension calciner (GSC). Using a secondary calciner in such a manner can increase throughput of the primary calciner and provide other advantages for the calcination process.

Abstract: The present disclosure relates to the treatment of produced water from SAGD operations or other thermal in situ hydrocarbon recovery operations. The innovative products and techniques have been developed by Baymag Inc, a subsidiary of Refratechnik Holding GmbH. For example, the disclosure relates to a silica reducer composition for use in warm or hot lime softeners or evaporators for treating produced water generated from in situ hydrocarbon recovery operations. The silica reducer composition has an enhanced combination of particle sizing and surface area for facilitating silica reduction while minimizing hydration. The silica reducer composition can be manufactured by calcining followed by milling and other optional process steps.