石墨的生产过程可分为两大类:天然石墨和合成石墨。以下是每种类型的生产工艺:
天然石墨生产工艺
天然石墨主要是从矿石中提炼出来的,其步骤如下:
1.采矿 :
从矿山中提取含石墨矿石,通常采用露天或地下采矿方法。
2.粉碎和研磨 :
开采的矿石最初粉碎,然后进行细磨,以达到所需的粒径。
3.浮选 :
采用浮选法从矿石中分离石墨。浮选利用石墨的疏水性,使其附着在气泡上,漂浮到表面,将其与杂质分离。
4.脱水和干燥 :
用过滤器和离心机将浮选精矿脱水。经脱水的石墨精矿随后干燥,以降低水分含量。
5.净化 :
为了获得高纯度石墨,干精矿可以经过化学处理(例如酸浸)来去除剩余杂质。
合成石墨生产过程
合成石墨通常来自含碳材料(如石油焦炭、沥青焦炭等)。)通过高温石墨化。生产过程包括以下步骤:
1.Raw Material Preparation:
Selecting suitable carbon-containing materials, such as petroleum coke, coal coke, or pitch coke. The raw materials are crushed and screened to achieve the desired particle size.
2.Mixing and Forming:
Mixing the crushed raw materials with a binder (such as coal tar pitch) to create a uniform mixture. The mixture is then molded or extruded into the desired shape, such as rods or blocks.
3.Baking:
The molded shapes are baked in a baking furnace at temperatures between 800-1200°C. During baking, volatile substances and some impurities are removed.
4.Impregnation:
The baked products are impregnated with pitch and then re-baked to increase density and mechanical strength.
5.Graphitization:
浸渍和再浸渍产品在石墨化炉中进行高温石墨化。石墨化温度通常在2500-3000℃之间。在高温下,碳原子重新排列形成石墨的结晶结构。
6.机器加工 :
将磨粒化材料加工成石墨电极、石墨铸铁等最终产品。
通过这些工艺,可生产不同纯度和规格的石墨材料,以满足各种工业需要。