冶炼有色金属使用的耐火材料工艺(三)
四、炼铅用耐火材料
铅的冶炼基本上采用烧结-鼓风炉法（即焙烧-还原冶炼法）。炉型为鼓风炉，铅锌密闭鼓风炉，氧气底吹炼铅炉和基夫赛特（KIVCET）法直接炼铅炉.
（1）鼓风炉，竖式圆筒状，炉身上部工作层为黏土砖砌筑；中部工作层一般用镁砖，镁铬砖或铬砖砌筑；炉身下部及风口区温度为1300℃，个别部位为 1500℃，使用条件苛刻，有水冷板保护，工作层一般使用致密黏土砖，高铝砖或镁铬砖，或高铝质浇注料。炉缸工作层用镁砖，镁铬砖或铬砖砌筑。由于铅液密度大，渗透力强，易使炉底砖上浮，因此采用高铝质磷酸盐结合捣打料捣制炉缸，使用效果较好。
（2）铅锌密闭鼓风炉，是处理铅锌氧化矿或铅锌混合硫化矿的新炉型，是直接冶炼生产铅和锌的热工设备。由密闭鼓风炉，冷凝器（即铅雾室）和烟道等部分组成。该炉炉缸工作层和炉腰水冷板衬里，一般采用镁铬砖砌筑，炉顶及与铅雾室连接处的斜道衬体等部位，普遍采用高铝水泥耐火浇注料现场浇注，也可做成预制块吊装砌筑。铅雾室的底和顶，采用致密黏土砖砌筑，也可用耐火浇注料浇灌。侧墙承受铅雾的冲刷和化学侵蚀作用，损毁较快，用黏土结合碳化硅砖砌筑。铅锌分离室的底和顶一般用致密黏土砖砌筑。铅液流槽和出铅槽的槽底，采用 Al₂O₃含量65%的高铝砖砌筑，槽壁用镁铬砖或铬砖砌筑，也可用同材质的浇注料浇注，形成整体性强的槽衬。槽盖板用高铝水泥浇注料预制块。
（3）氧气底吹炼铅炉，用铅精矿直接炼铅的热工设备。呈长形圆筒状，水平放置在两个托圈上，可以回转90°，炉子长约 22m，分为还原区和氧化区，二者间设有隔墙。其下部留有孔洞，使两区相通，氧化区安有氧气喷嘴，上方设有装料口。还原区安装套筒式喷嘴等。炼铅炉的熔池，渣线区，隔墙，装料口及喷嘴对面的炉墙等部位，一般采用熔铸镁铬砖砌筑，其余部位采用直接结合镁铬砖或烧成镁铬砖砌筑。
（4）基夫赛特法直接炼铅炉，将焙烧和熔炼合并在同一炉中完成。它由直筒状熔炼塔和电炉两部分组成，二者共用炉膛，用水冷式隔墙隔开。隔墙插入熔池深度为200~400mm。该炉的电炉内衬及熔炼塔高温区受高温及化学侵蚀作用，渣线，电极孔及隔墙插入熔池中损毁较快，因此炉子工作层全部采用镁铬砖砌筑，易损部位还采用水冷铜套保护。水冷板隔墙也可在板上焊接锚固钉，浇注或捣打镁铬质不定形耐火材料。
Refractory Materials for Smelting non-ferrous metals (3)
4.Refractory materials for lead smelting
The smelting of lead basically adopts the sinter – blast furnace method (that is, the roasting – reduction smelting method). The furnace types are blast furnace, lead-zinc closed blast furnace, oxygen bottom blow furnace and KIVCET direct lead smelting furnace.
1) Blast furnace, vertical cylinder, the working layer of the furnace body is made of clay brick; The middle working layer is generally made of magnesia brick, magnesia chrome brick or chrome brick masonry; The temperature of the lower part of the furnace body and the tuyere area is 1300℃, and the individual parts are 1500℃. The use conditions are harsh, and the water-cooled plate is protected. The working layer is generally made of dense clay brick, high aluminum brick or magnesia chrome brick, or high aluminum castable. The working layer of the hearth is constructed of magnesia brick, magnesia chrome brick or chrome brick. Because of the high density and strong permeability of lead liquid, it is easy to make the bottom brick float, so the use of high aluminum phosphate combined with ramming material to pound the furnace cylinder is better.
(2) Lead-zinc closed blast furnace, is a new furnace type for processing lead-zinc oxide ore or lead-zinc mixed sulfide ore, and is a thermal equipment for direct smelting and production of lead and zinc. It is composed of sealed blast furnace, condenser (i.e. lead fog chamber) and flue. The working layer of the furnace cylinder and the water-cooled plate lining of the furnace waist are generally made of magnesia chrome brick, and the sloping lining body of the furnace top and the joint of the lead fog chamber are generally cast with high aluminum cement refractory castable on site, and can also be made into prefabricated blocks. The bottom and top of the lead fog chamber are laid with dense clay bricks and can also be poured with refractory castable. The side wall is damaged faster by the scour of lead mist and chemical erosion, and is built with clay combined with silicon carbide brick. The bottom and top of the lead-zinc separation chamber are generally constructed with dense clay bricks. The bottom of the lead bath and the lead bath are laid out in high aluminum bricks with 65% Al₂O₃, and the walls of the bath are laid out in magnesia-chrome bricks or chrome bricks, or castable of the same material to form a strong integrated groove lining. High alumina cement castable prefabricated block for trough cover plate.
(3) Oxygen bottom blow lead furnace, thermal equipment for direct lead smelting with lead concentrate. It is in the shape of a long cylinder and placed horizontally on two supporting rings, which can be rotated 90°. The furnace is about 22m long and is divided into a reduction zone and an oxidation zone, and a partition wall is provided between the two. The lower part is provided with holes to communicate the two zones, the oxidation zone is provided with an oxygen nozzle, and the charging port is provided above. Install sleeve nozzles in the reduction area. The melting pool, slag line area, partition wall, charging port and the furnace wall opposite the nozzle of the lead smelting furnace are generally constructed with fused magnesia chrome brick, and the rest are directly combined with magnesia chrome brick or burned magnesia chrome brick.
(4) Kifset method direct lead smelting furnace, roasting and smelting combined in the same furnace to complete. It consists of two parts: a straight cylindrical melting tower and an electric furnace, which share a furnace and are separated by a water-cooled partition wall. The depth of the partition wall inserted into the molten pool is 200~400mm. The lining of the furnace and the high temperature area of the melting tower are affected by high temperature and chemical erosion, and the slag line, electrode hole and partition wall are damaged quickly when inserted into the melting pool, so the working layer of the furnace is all made of magnesia-chrome brick, and the vulnerable parts are also protected by water-cooled copper sleeves. The water-cooled plate partition wall can also be welded on the plate anchor nails, cast or rammed magnesium chromium amorphous refractory material.
