Abstract: It was pointed out that aluminate hydrate(AH) wash l iquor was favor to red mud washing only if its total soda concentration was less t han that of red mud wash liquor. The permitted maximum total soda concentration in AH wash liquor was 61.56g/L according to actual production data of Pinggu o Alumina Refinery in the 1st half year of 2000. Three schemes of dealing with AH wash liq uor of high soda concentration were analyzed and compared. The results show th at when the AH wash liquor of total soda concentration 95.06g/L is transferred d irectly to dilution tank, soda concentration in overflow of the 1st mud washer c ould be lowered by about 6g/L and soda loss in red mud attached liquor could be lo we red by 0.25 kg Na2O per ton of alumina and therefore saving cost of about 549 000 RMB per year; moreover, suspension in AH wash liquor could be re-dissolved in to diluted liquor and it is favor not only to rise pregnant liquor Rp andimprove precipitation process, but also to avoid alumina loss cost of about 353?000 RMB per year by the suspension settling into red mud. The simple and available sch eme for AH wash liquor process change was also proposed.
Calculation of permitted maximum total soda mass concentration in aluminate hydrate wash liquor and process change scheme
Abstract:
It was pointed out that aluminate hydrate (AH) wash liquor was favor to red mud washing only if its total soda concentration was less than that of red mud wash liquor. The permitted maximum total soda concentration in AH wash liquor was 61.56?g/L according to actual production data of Pingguo Alumina Refinery in the 1st half year of 2000. Three schemes of dealing with AH wash liquor of high soda concentration were analyzed and compared. The results show that when the AH wash liquor of total soda concentration 95.06?g/L is transferred directly to dilution tank, soda concentration in overflow of the 1st mud washer could be lowered by about 6?g/L and soda loss in red mud attached liquor could be lowered by 0.25?kg Na 2O per ton of alumina and therefore saving cost of about 549?000 RMB per year; moreover, suspension in AH wash liquor could be re dissolved into diluted liquor and it is favor not only to rise pregnant liquor R p and improve precipitation process, but also to avoid alumina loss cost of about 353?000 RMB per year by the suspension settling into red mud. The simple and available scheme for AH wash liquor process change was also proposed.