Mineral Processing Knowledge Q&A

Author: Chief Editor: Lin Renying et al.
Publisher:
Publish Date: 2001-11-01
Features: This book introduces the basic knowledge of mineral processing technology in the form of questions and answers, including general concepts, crushing and screening, grinding and classification, gravity separation, magnetic and electric separation, flotation, chemical separation, dewatering of mineral processing products, sampling and inspection in mineral processing processes, and tailings treatment, comprising nine chapters. Originally, there were only eight chapters, but in this revised edition, chemical separation was supplemented and revised, and a ninth chapter on tailings treatment was added. This book is suitable for mineral processing workers and vocational school students. Students of mineral processing majors in universities and colleges, as well as cadres and technical personnel engaged in mineral processing, can also refer to it. This book has been reviewed by Associate Professor Huang Hewei of University of Science and Technology Beijing, Professor Guo Bingwen of Wuhan Institute of Chemical Technology, and Senior Engineer He Shanshu of Daye Non-ferrous Metals Co., Ltd.
Excerpt:
[1] What is the purpose and significance of mineral processing? Ore mined from the ground is called run-of-mine ore, which is generally composed of useful minerals and gangue. The grade of run-of-mine ore is usually low and cannot be directly smelted. It needs to be processed first to remove most of the gangue and harmful components, allowing the useful minerals to concentrate into concentrate for further use. The process of processing run-of-mine ore is called mineral processing. For example, black tungsten ore generally contains a large amount of gangue, such as quartz. Through mineral processing, a large amount of quartz-like gangue is removed, allowing the tungsten mineral components to concentrate into a concentrate product. Some ores contain elements harmful to the smelting process, such as sulfur and phosphorus in iron concentrate. Their content cannot be too high, otherwise it will make pig iron brittle. Especially in some polymetallic coexisting ores, the various metal components contained, such as Cu-Pb-Zn-Fe, often mutually hinder each other during smelting. Only after mineral processing to obtain multiple concentrate products can they be smelted separately. In addition, mineral processing also has significant technical and economic effects on smelting. For example, if the grade of copper concentrate is increased from 15% to 16%, the smelting recovery rate can be increased by 0.1–0.15%, the production capacity can be increased by 6–8%, and fuel consumption can be reduced by 6–7%. For instance, if the grade of iron concentrate is increased by 1%, the output of blast furnace pig iron can be increased by 2.5%, and the coke ratio can be reduced by 1.5%. In summary, the purpose of mineral processing is to remove a large amount of gangue and harmful elements from the ore, allowing the useful minerals to concentrate or separating various useful minerals that coexist, obtaining one or more concentrate products of useful minerals. It can be seen that mineral processing plays a very important role in developing the mining industry and making full use of mineral resources.
[2] What is a mineral? What are the common minerals? A mineral is a natural element or natural compound formed after natural physical and chemical actions and biochemical actions in the Earth's crust, with a fixed chemical composition and physicochemical properties. Minerals are components of rocks and ores. In addition to a few natural elements such as natural gold (Au), natural silver (Ag), natural copper (Cu), natural sulfur (S), graphite (C), and diamond (C), most minerals are natural compounds, such as magnetite (Fe3O4), quartz (SiO2), galena (PbS), and chalcopyrite (CuFeS2). The morphology of most minerals is solid, with a few being liquid (such as natural mercury) or gaseous (such as carbon dioxide). Currently, there are more than 3,500 known minerals, and only about 200 can be utilized under existing technical conditions. The more common minerals are listed in Table 1-1.
[3] What is a rock? What is an ore? The substances constituting the Earth's outer shell (lithosphere) are called rocks. Rocks are mineral aggregates formed under various geological processes, consisting of one or more minerals. Rocks composed mainly of a single mineral are called monomineral rocks, such as limestone, which is composed of more than 95% CaCO3. Rocks composed of two or more minerals are called polymetallic rocks, such as granite, which is composed of feldspar, quartz, and mica. Rocks are divided into three major categories based on their origin: igneous rocks, sedimentary rocks, and metamorphic rocks. An ore is defined as a rock that can be industrially extracted metals and other compounds under current technical conditions. It must be pointed out that the definition of an ore is relative, not only depending on current technical conditions but also on the specific resources and economic needs of a country. In ores that contain only one useful mineral or metal, they are called single ores, such as copper ores containing only one useful copper mineral. Ores containing two or more useful minerals or metals are called composite ores, such as lead-zinc ores and copper-cobalt-nickel ores.
[4] What is a useful mineral? What are its uses? A useful mineral is a mineral, ore, or rock that can be utilized. Useful minerals are used in every sector of the national economy, or in products processed from useful minerals. Since all metals are extracted from useful minerals, and mechanical industries, electrical industries, shipbuilding, railway transportation, aviation, and other industrial sectors cannot do without various metals. It can be seen that useful minerals are of great significance in the national economy.
[5] What is gangue? What is surrounding rock? What is waste rock? The part of the ore that has no use value or cannot be utilized is called gangue, such as tungsten ore, which is often formed in quartz veins. Such quartz veins are called gangue. The rocks surrounding the ore body are called surrounding rocks. The surrounding rocks above the ore body are called the upper plate surrounding rock or roof rock, and the surrounding rocks below the ore body are called the lower plate surrounding rock or floor rock. The rocks embedded in the ore body are called interlayers.