normal style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21.75pt; tab-stops: 106.95pt 144.0pt">第-段焙烧通常称为除砷段。在此,温度控制在925OF,氧气供入量控制在最低值。为了保证以三价神的形态除去砷,通常在焙烧酌初期要保持还原状态,因为过剩氧的存在会助长三阶砷氧化为五价砷,这种五价砷就会以三价铁的砷酸盐表面膜形态留在焙砂上,从而推迟或妨碍砷的进-步挥发,以及影响焙砂中金的浸出。
normal style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21.75pt; tab-stops: 106.95pt 144.0pt">第二殴焙烧称为氧化焙烧。在此流态床焙烧过的物料在活性氧化条件下进-步氧化,并使硫进-步除去,然而,这里不可能达到也不希望发生死焙烧,因为硫的完全除去,势必促进铁继续氧化成磁铁矿,并留在焙砂的微孔内,从而妨碍氰化液的渗透。
normal style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21.75pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt" align=center>表1 工厂处理的标准分析结果
normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>名 称 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>吨/日 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>Au(盎司/吨) | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>Fe | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>S | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>As | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>Sb |
normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>磨矿机给矿 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>1250 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>0.19 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>6.60 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>2.2 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>0.85 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>0.04 |
normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>浮选精矿 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>130 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>1.60 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>23.00 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>17.5 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>7.6 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>0.18 |
normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>焙砂 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>100 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>2.00 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>27.80 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>2.5 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>1.0 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>0.13 |
normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>静电收尘器粉尘 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>22 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>1.43 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>18.00 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>2.75 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>2.29 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>0.30 |
normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>布袋收尘器粉尘 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>15 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>0.12 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>1.75 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>0.50 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>70.00 | normal style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 11pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt; mso-line-height-rule: exactly" align=center>0.50 |
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normal style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21.75pt; TEXT-ALIGN: center; tab-stops: 106.95pt 144.0pt" align=center>气体净化作业简史
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normal style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21.75pt; tab-stops: 106.95pt 144.0pt">贾特矿气体净化最初于1951年10月建起了-座低温柯特奈尔型静电除尘器,用以捕收焙砂粉尘及从爱德华型焙烧炉出口气体中冷凝下来的三氧化二砷。1952年初安装了第-台流态化、焙烧炉,-座直径为
normal style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21.75pt; tab-stops: 106.95pt 144.0pt">看来就金的提取而言,第-段流态化焙烧炉是严格控制空气,以保持在中等的还原性气氛下进行操作,从而使炉子出口气体含有高浓度的二氧化硫(基本上不是三氧化硫)。当电收尘器的温度在SO2仍为气体,而SO3接近于冷凝温度时,不导电的砷粉尘粒表面吸附SO3,这就使得悬浮的粉尘变为导电的而得以回收。在焙烧炉出口气体中SO3量不高可使被冷凝下来的砷的不导电尘粒穿过电除尘器从烟囱排出。
normal style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21.75pt; tab-stops: 106.95pt 144.0pt">1955年建起了第二座柯特奈尔型高温静电除尘器,在原来的低温电收尘器中冷凝下来的砷被捕收以前,用它来选择性地回收焙砂尘中所含的金。这两台(热的和冷的)电除尘器串联作业,使收尘效率得到了提高,但冷凝下来的砷粒,对于能在低温电除尘器中回收而言,其导电性是不够的。曾试图提高焙烧炉出口气体中三氧化硫的含量未能获得成功。最后As2O3和焙砂尘的混合回收率下降到60%,这就必须使这两台电除尘器在低温下操作。
normal style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21.75pt; tab-stops: 106.95pt 144.0pt">1957年-台小型的布袋收尘器就-部分焙烧炉气作了试验。结果表明,这种装置砷的捕收效率高达99%,且布袋使用寿命令人满意。
normal style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21.75pt; tab-stops: 106.95pt 144.0pt">1958年安装了-座扩大的两段流态化固体焙烧炉。与此同时-座有8个隔室的标准30-德拉科型袋式收尘器投入作业中。当时用它来捕收炉气中的焙砂尘和冷凝下来的三氧化二神。在这座新建的流态化固体焙烧炉运行情况良好后,这种科特奈尔型静电收尘器就作为-台高温电除尘器那样推动烟气流动。从此选择性地捕收含金的焙砂尘和冷凝下来的三氧化二砷才付诸实践。1962年春天,原有的低温柯特奈尔型静电除尘器进行了改造,目前它是与高温电除尘器并联进行作业。