有色金属在国民经济中占有极其重要的地位，应用十分广泛。有色金属的种类也非常多，可分为重金属，轻金属和稀土金属三大类。生产量大，而且普遍应用：铜、铝、铅、锌、镍等5 种有色金属。冶炼有色金属的方法多种多样，使用炉窑的类型很多，一般分为熔炼炉，精炼炉和熔铸炉。本节仅选择生产量大，使用耐火材料有代表性的几种有色金属做以下介绍：一、炼铝用耐火材料炼铝工艺过程复杂，使用的炉窑种类较多，但炉子工作温度都比较低（最高1200℃），使用条件也不太苛刻，所以一般采用黏土砖和高铝砖，即可满足生产要求。随着耐火材料技术进步，近年来炼铝工艺过程用的耐火材料也有所改进，大致如下：（1）生产氧化铝的回转窑及闪速炉，首先要将天然铝土矿变成氢氧化铝，再将氢氧化铝经950~1200℃煅烧成氧化铝，一般采用回转窑和闪速炉煅烧。回转窑的绝热层靠窑壳铺一层耐火纤维毡，然后用硅藻土，漂珠砖或黏土轻质砖砌筑，现在有些单位改为轻质耐火浇注料。预热带用黏土砖，烧成带、冷却带用高铝砖，现在改为磷酸盐结合高铝不烧砖。闪速炉是先在炉壳上焊接耐热钢锚固钉或陶瓷锚固件，然后铺一层20mm厚的耐火纤维毡，最后浇注 200~300mm厚的耐火浇注料。

（2）电解氧化铝，用氧化铝和冰晶石熔剂组成电解质，将电解质溶液装进电解槽中通电，在950~970℃的温度下，使氧化铝分解为金属铝和氧。电解槽靠槽壳铺一层耐火纤维毡，接着砌漂珠砖，或轻质浇注料，再砌黏土砖，工作层用碳或氮化硅结合碳化硅砖，能抵抗铝液的渗透，氟化物和电解质及熔融钠盐的侵蚀，延长使用寿命。槽壁和槽底工作层采用炭块砌筑或用炭质捣打料，捣打成整体衬。（3）铝熔炼，主要有反射炉，转筒炉和感应电炉等，操作温度一般为700~1000℃。其炉衬的损毁主要是铝液的渗透和冲刷所致。一般使用黏土砖，高铝砖及刚玉莫来石砖砌筑。近年来，普遍使用高铝质浇注料和耐火可塑料，炉子寿命较长为1~5年。（4）铝精炼，电解槽操作温度为720~800℃，槽壁用镁砖砌筑，其余为黏土砖和高铝砖。二、炼镍用耐火材料炼镍工艺过程亦较复杂，先将硫化镍或镍精矿制成烧结矿，再熔炼成低冰镍，后经吹炼制成高冰镍，最后电解成金属镍。现将这个过程的热工设备所用耐火材料简述如下：（1）焙烧炉，炉子操作温度一般低于1400℃，无化学侵蚀作用，因此一般采用黏土砖砌筑，个别部位用高铝砖。（2）熔炼炉，有鼓风炉，矿热电炉，反射炉和闪速炉等炉型。由于闪速炉冶炼强度高，能耗低和保护环境等优点，是应用最多的炉型。闪速炉的工作温度最高可达1600℃，炼镍时使用条件较苛刻，熔渣中氧化镁和氧化铁含量较高，因此内衬损毁较快，国际上普遍使用优质高纯或电熔镁铬砖砌筑。

  鼓风炉炉身上部用黏土砖砌筑，中、下部有水冷套，并衬砌致密黏土砖。炉缸底和侧壁用黏土砖做工作层，非工作层用耐火浇注料，放低冰镍口和放渣口周围内衬用镁砖或镁铬砖砌筑。

  矿热电炉操作温度为1400℃左右，炉底的非工作层用耐火浇注料做成锅底状，然后用黏土砖砌筑非工作层，用镁砖砌筑工作层。炉墙渣线以上用黏土砖砌筑，渣线及以下工作层用镁砖及镁铬砖砌筑。为了提高渣线及放低冰镍口的寿命，采用水冷铜套强制冷却，炉顶可采用高铝质浇注料，使整体性好，结构稳定。

  （3）吹炼炉，是将低冰镍炼成高冰镍的热工设备，主要有转炉和反射炉两种炉型。转炉为圆筒形，分立式和卧式，我国普遍用卧式转炉，吹炼时工作温度为1350~1500℃，每炉吹炼时间约7~10h，内衬一般采用全合成镁铬砖，预反应镁铬砖和铝铬渣砖。在转炉中损毁最严重的是风口及风口区，采用镁铬砖砌筑，寿命仅为18炉左右，而用铝铬渣制造的一种铝镁铬风口砖，使用寿命可达50炉。反射炉为长方形，卧式，炉底工作层由石英砂捣打而成，炉墙下部工作层一般采用镁砖砌筑，其余则用硅砖，使用寿命约3个月，如果渣线及以下部位工作层全部采用镁砖，其余部位工作层采用高铝砖，各部位非工作层全部用黏土砖，使用寿命可达1~1.5 年。

Refractory materials for Smelting non-ferrous metals (1)

    Non-ferrous metals occupy an extremely important position in the national economy and are widely used. There are also many types of non-ferrous metals, which can be divided into three categories: heavy metals, light metals and rare earth metals. Large production, and widely used: copper, aluminum, lead, zinc, nickel and other 5 kinds of non-ferrous metals. There are a variety of methods for smelting non-ferrous metals, and many types of furnaces are used, generally divided into melting furnaces, refining furnaces and melting and casting furnaces. This section only selects several non-ferrous metals with large production capacity and representative refractory materials to make the following introduction: First, aluminum refractory aluminum smelting process is complex, the use of more types of furnaces, but the furnace operating temperature is relatively low (up to 1200 ° C), the use of conditions are not too harsh, so the general use of clay bricks and high aluminum bricks, can meet the production requirements. With the progress of refractory technology, in recent years, the refractory materials used in the aluminum smelting process have also been improved, roughly as follows: (1) the rotary kiln and flash furnace for the production of alumina, first of all, the natural bauxite must be turned into aluminum hydroxide, and then the aluminum hydroxide is calcined into aluminum oxide by 950~1200℃, generally using rotary kiln and flash furnace calcination. The insulation layer of rotary kiln is laid on a layer of refractory fiber felt against the kiln shell, and then it is laid with diatomaceous earth, bleached bead brick or clay lightweight brick, and some units are now changed to light refractory castable. Clay bricks for pre-heating, high aluminum bricks for firing belt and cooling belt, now it is changed to phosphate bonded high aluminum unfired bricks. Flash furnace is to weld heat-resistant steel anchor nails or ceramic anchors on the furnace shell, then lay a layer of 20mm thick refractory fiber felt, and finally cast 200~300mm thick refractory castable.

  (2) electrolytic alumina, consisting of electrolyte with alumina and cryolite flux, the electrolyte solution is put into the electrolytic cell and electrified, and the alumina is decomposed into metal aluminum and oxygen at a temperature of 950~970 ° C. The electrolytic cell is laid with a layer of refractory fiber felt on the tank shell, then built with floating bead bricks, or lightweight castable, and then built with clay bricks. The working layer is made of carbon or silicon nitride combined with silicon carbide bricks, which can resist the penetration of aluminum liquid, the erosion of fluoride and electrolyte and molten sodium salt, and extend the service life. The working layer of the tank wall and the bottom of the tank is made of carbon block masonry or carbon ramming material, and the whole lining is rammed. (3) Aluminum smelting, mainly reverberatory furnace, rotary furnace and induction furnace, the operating temperature is generally 700~1000℃. The damage of the lining is mainly caused by the penetration and erosion of liquid aluminum. Generally used clay brick, high alumina brick and corundum mullite brick masonry. In recent years, high aluminum castable and refractory plastic are commonly used, and the furnace life is longer than 1 to 5 years. (4) Aluminum refining, the operating temperature of the electrolytic cell is 720~800 ° C, the wall of the cell is built with magnesium brick, and the rest is clay brick and high aluminum brick. Second, nickel smelting refractory nickel refining process is also more complex, the first nickel sulfide or nickel concentrate into sinter, and then smelting into low-ice nickel, after blowing into high-ice nickel, and finally electrolysis into metal nickel. The refractory materials used in the thermal equipment of this process are described as follows: (1) baking furnace, the operating temperature of the furnace is generally lower than 1400 ° C, no chemical erosion, so the clay brick masonry is generally used, and high aluminum bricks are used in individual parts. (2) Smelting furnaces, there are blast furnaces, ore thermal electric furnaces, reverberatory furnaces and flash furnaces and other furnace types. Because of the advantages of high smelting intensity, low energy consumption and environmental protection, flash furnace is the most used furnace type. The working temperature of the flash furnace can reach up to 1600℃, the use of nickel smelting conditions are harsh, and the magnesium oxide and iron oxide content in the slag is high, so the lining is damaged faster, and the high quality and high purity or electromolten magnesia chrome brick is widely used in the world.

  The body of the blast furnace is made of clay bricks, and the middle and lower parts have water-cooled sleeves, and are lined with dense clay bricks. The bottom and side walls of the hearth are made of clay bricks as the working layer, the non-working layer is made of refractory castable, and the inner lining around the ice nickel opening and slag opening is made of magnesia brick or magnesia chrome brick.

  The operating temperature of the ore-heat electric furnace is about 1400℃. The non-working layer at the bottom of the furnace is made into a pot shape with refractory castable, and then the non-working layer is laid with clay brick and the working layer is laid with magnesium brick. The above slag line of the furnace wall is laid with clay brick, and the working layer below the slag line is laid with magnesia brick and magnesia chrome brick. In order to improve the life of slag line and ice nickel outlet, water-cooled copper jacket is used to force cooling, and high aluminum castable can be used on the top of the furnace, so that the integrity is good and the structure is stable.

  (3) The blowing furnace is a thermal equipment for refining low-ice nickel into high-ice nickel, and there are mainly two types of furnace types: converter and reflex furnace. The converter is cylindrical, vertical and horizontal, horizontal converter is widely used in our country, the working temperature during blowing is 1350~1500℃, the blowing time of each furnace is about 7~10h, and the lining is generally made of synthetic magnesium-chromium bricks, pre-reacted magnesium-chromium bricks and aluminum-chromium slag bricks. The most serious damage in the converter is the tuyere and tuyere area, the use of magnesia chrome brick masonry, life is only about 18 furnace, and an aluminum-magnesia chrome tuyere brick made of aluminum chrome slag, the service life of up to 50 furnace. The reverberatory furnace is rectangular, horizontal, the bottom working layer of the furnace is made of quartz sand ramming, the lower working layer of the furnace wall is generally made of magnesium brick, the rest is made of silicon brick, the service life is about 3 months, if the slag line and the following parts of the working layer are all made of magnesium brick, the rest of the working layer is made of high aluminum brick, all parts of the non-working layer are made of clay brick, the service life can reach 1~1.5 years.