Adsorption of Trisiloxane Surfactant for Selective Flotation of Scheelite from Calcite at Room Temperature.

The separation and enrichment of scheelite from calcite are hindered by the similar active Ca sites of scheelite and the calcite with calciferous gangue. Herein, a novel trisiloxane surfactant, -(2-aminoethyl)-3-aminopropyltrisiloxane (AATS), was first explored and synthesized and recommended as the collector for the flotation separation of scheelite from calcite. The micro-flotation and mixed binary mineral flotation tests showed that AATS had excellent collection performance for scheelite and high selectivity for calcite within a wide pH range.

Recovery of wolframite from tungsten mine tailings by the combination of shaking table and flotation with a novel "crab" structure sebacoyl hydroxamic acid.

Tailings ponds for gangue mineral storage are widely recognized as a dangerous source of toxic minerals and heavy metal-bearing solution. Therefore, recovering valuable minerals and critical elements from tailings is an important means to protect the environment in an economic way. Wolframite tailings usually contain a considerable amount of tungsten resources, but the presence of high content of kaolinite sludge makes it very difficult to recycle wolframite.

Nitrogen removal from domestic wastewater in a novel hybrid anoxic-oxic biofilm reactor at different reflux ratios.

A lab-scale hybrid anoxic-oxic biofilm reactor (HAOBR) with one anoxic compartment and two oxic compartments in sequence was constructed to treat domestic wastewater in this study. Performance of the HAOBR was evaluated at 25°C and hydraulic retention time 12 hr with reflux ratio increased from 100% to 300% by stages. The results showed that COD, , and TN removal presented an increasing trend with the increase of reflux ratio by stages.