无机盐阳离子对粉煤灰浮选泡沫稳定性的影响研究

Influence of inorganic salt on flotation froth stability of coal fly ash

粉煤灰中矿物组成的自然属性使得浮选脱炭体系的泡沫稳定性较差,从而影响了未燃炭的有效脱除。通过添加无机盐阳离子的方式来改变粉煤灰浮选矿浆体系的液相性质,研究了不同离子种类和含量对两相泡沫和粉煤灰浮选三相泡沫稳定性的影响,并进行了浮选验证。研究结果表明:无机盐阳离子的添加提高了泡沫的稳定性,阳离子价态越高,这种稳定作用就越明显。利用泡沫稳定性调节中的离子效应,对采自湖北黄石的粉煤灰样品进行了浮选脱炭的验证试验,结果表明:Fe3+对泡沫的稳定作用有效提高了粉煤灰的浮选脱炭效果,与空白浮选体系相比,在Fe3+浓度为3 mmol/L的条件下,浮选低炭灰烧失量由8.85%降低至5.57%,炭脱除率由41.94%提升至74.55%;与添加Fe3+的浮选体系相比,Mg2+和Na+对浮选指标的提高作用依次减弱。

Specific nature property of mineral composition in coal fly ash is the key factor to depress froth stability of unburned carbon flotation.This study intends to improve froth stability via the addition of inorganic salt cations.Three different inorganic salt cations(Na+,Mg2 +,Fe3 +) were added into both solutions with only frother and flotation pulp system with ash particles.The influence of inorganic salt cations on foam and froth stability was studied systematically.The results indicate that the addition of salt cations improves the stability of gas-liquid foam and gas-liquid-solid froth.The stabilization function of Fe3 +to the foam or froth is stronger than Mg2 +and Na+.Based on the above study,the flotation of coal fly ash from Hubei province of China was conducted.Compared with flotation system with no salt cations,the LOI of low carbon product could be reduced from 8.85% to 5.57% in the flotation system with 3 mmol / L Fe3 +.The unburned carbon removal rate of low carbon product is improved from 41.94% to 74.55%.Compared with flotation system with Fe3 +,the function of Mg2 +and Na+to the floatation indexes is weakened in due order.