| 摘要 |
<p>1,017,715. Scrubbing gas containing zinc compounds. METALLGESELLSCHAFT A.G. March 6, 1964 [March 7, 1963], No. 9683/64. Heading B1R. Dust is removed from the exhaust gases evolved in the self-fluxing smelting of lead ores by washing the gas in a first Venturi scrubber with an acid solvent selective for zinc e.g. dilute sulphuric or sulphurous acid and then washing the gas in a second Venturi scrubber with a liquor to neutralize the acidic components of the gas and the first scrubbing liquid and to scrub out the remaining dust; the second washing liquor may be aqueous sodium hydroxide or carbonate. Into rotary furnace I is charged a self-fluxing sinter containing lead, zinc, sulphur, returns and fly ash; the effluent gases containing suspended fly ash (lead, zinc, sulphur and iron) are precooled in 4 by means of water through spray 5 and washed in first Venturi scrubber 6 with dilute H 2 SO 4 wherein the zinc oxide and lead oxide components are predominantly removed. The contaminated washing solution is cycled through regeneration system 7, 8, 10, 11, 12 and reintroduced to scrubber 6, while treated gas passes through mist collecter 7 and hence to second Venturi scrubber 7 wherein it is washed with 10% aqueous NaOH. Spent NaOH is cycled through regeneration system 17, 20, 22, 23 and returned to scrubber 16. Purified gas is withdrawn from the plant through mist collector 17 and fan 18.</p> |
