The mine in the 1950's designed by the Beijing Nonferrous Metallurgy Design Research Institute, design capacity 4000t / d. 9 to 17 Danpu Shi mineral hardness, density 3.1t / m 3, bulk density 1.8t / m 3, the natural angle of repose of 38 °. In order to reduce the granularity of crushed ore products and improve the processing capacity of the mill, the concentrator has changed the three-stage open-circuit process to a three-stage and one-closed process. The current treatment capacity is only 1200t/d. Compared with the design of 4000t/d, the equipment has a large surplus capacity. In addition, after the closed road, the factory has cracks, and the three-stage open circuit is still being restored. Due to careful operation and management, the final crushing granularity is still controlled at less than 20mm and accounts for about 85%. PERSONAL PROTECTION Welding Protection,Auto-Darkening Welding Helmet,Welding Gloves,Welding Glasses Changzhou Edaweld Trading Company Limited , https://www.edaweld.com
(1) The nature of the ore: Copper Copper Mine in contact metamorphic temperature was allowed to warm to account deposits. Types of copper mining industry skarns, diorite copper, copper pyrite three types, each type 65:15:25 ratio, respectively.
The copper-bearing skarn is mainly composed of garnet, containing diopside , magnetite, chalcopyrite, pyrite, calcite and the like. Copper diorite plagioclase, hornblende mainly chalcopyrite more with the quartz veins. The type of copper-bearing pyrite is mainly pyrite and pyrite, and contains chalcopyrite, magnetite, porphyrite, quartz, calcite and the like.
The copper-bearing minerals in the sulfide ore are mainly chalcopyrite, followed by porphyrite and chalcopyrite. Other metallic minerals are mainly magnetite, pyrite, hematite followed, marcasite, sphalerite, molybdenite, soft manganese ore. Non-metallic minerals garnet, calcite, quartz, tremolite, actinolite, plagioclase, epidote, chlorite, talc, apatite, sericite and the like.
Chalcopyrite is mostly in the form of disseminated and fine veins, and a few are symbiotic with the porphyrite, producing a ring-like shape. There are still a few chalcopyrite particles encased in magnetite. The general granules of chalcopyrite are 0.25~0.33mm, the smallest is 0.003mm; the general granules of porphyrite are 0.13~0.17mm, and the smallest one is 0.00167mm.
Most of the oxidized ore is yellow-brown-red-brown ore, loose and porous. When it is strongly oxidized, it is produced in powder form. Among them, copper minerals are mainly chalcopyrite and chalcopyrite, followed by malachite, porphyrite, copper blue and so on. Copper mineral particles are generally 0.08~0.25mm.
Ore dressing plants, multi-element analysis of the concentrate and tailings table below, the phase analysis table below. 
(2) Process flow: The ore is derived from the open pit mine and the pit mine. The open air is now over, and all the pits are treated.
The original design of the crushing process is a three-stage open circuit. After the production, due to the large water content of the ore, the production cannot be carried out, and the washing facilities are added. After many improvements, the crushing and washing process of the washing is set up before the coarse crushing and before the fine crushing. The process is to wash the ore before the coarse crushing of the sieve and the high-pressure water, and pre-screening and grinding again before fine crushing. Under the washing sieve, it is less than 20mm and enters three Ñ„2400 single spiral classifiers (two coarse crushing muds and one fine crushing muddy one), and the spiral return sand is directly sent to the powder mine bin by belt conveyor. The ore is washed by two sections to ensure the normal operation of the crushed ore production. This is a good reference for the concentrating plant that has not considered washing the mine and has to add additional washing afterwards. The broken washing process is shown in the figure below.
It is essential that the operator and helpers be properly clothed and protected because of the heat, ultra-violet rays, and sparks, produced by the arc welder (See Figure 3). For body protection a pair of fire retardant long sleeved coveralls without cuffs is a good choice. Always avoid clothing with tears, snags, rips, or worn spots as these are easily ignited by sparks. The sleeves and collars should be kept buttoned. The hands should be protected with leather gauntlet gloves. A pair o high top leather shoes, preferably safety shoes, is good protection for the feet. If low shoes are worn the ankles should be protected by fire resistant leggings. Eyes should be protected by transparent goggles if the person wears prescription glasses or safety glasses if not. A welding helmet or hand shield with filter plate and cover plate is mandatory for eye protection from the harmful rays of the arc. The filter plate should be at least shade #10 for general welding up to 200 amps. However, certain operations such as carbon-arc welding and higher current welding operations require darker shades. Never use a helmet if the filter plate or cover lens is cracked or broken. A flame-proof skull cap to protect the hair and head as well as hearing protection in noisy situations is recommended.
Plastic disposable cigarette lighters are very dangerous around heat and flame. It is very important that they not be carried in the pockets while welding. Always provide protection to bystanders or other workers by welding inside a properly screened area, if possible. If unable to work inside a screened area then protection to others should be provided by a portable screen or shield, or by their wearing anti-flash goggles.
SAFE OPERATION OF THE WELDER
It is important that anyone operating an arc welder be instructed on its safe use by a qualified teacher or welder.
Because of their potentially explosive nature, we strongly recommend that no welding, cutting, or hot work be attempted on used drums, barrels, tanks, or other containers under any circumstances.
If possible, work to be welded should be placed on a firebrick surface at a comfortable height. Welding should never be done directly on a concrete floor. Heat from the arc can cause steam to build-up in the floor which could cause an explosion. The welder cables should be positioned so that sparks and molten metal will not fall on them. They should also be kept free of grease and oil and located where they will not be driven over.
Electric welders can kill by electric shock. If the welding operation must be done on steel or other conductive material an insulating mat must be used under the operator. If the welding area is wet or damp or the operator is actively perspiring then he/she should wear rubber gloves under the Welding Gloves.
It is easier and safer to establish an arc on a clean surface than a dirty or rusty one. Therefore, metal should always be thoroughly cleaned by wire brushing or other method prior to welding. When chipping slag or wire brushing the finished bead the operator should always be sure to protect his eyes and body from flying slag and chips. Unused electrodes and electrode stubs should not be left on the floor as they create a slipping hazard. Hot metal should be handled with metal tongs or pliers. When quenching hot metal in water it should be done carefully to prevent painful burns from the escaping steam. Any metal left to cool should be carefully marked "HOT" with a soapstone. When welding is finished for the day or suspended for any length of time electrodes should be removed from the holder. The holder should be placed where no accidental contact could occur, and the welder should be disconnected from the power source.
SAFETY PRECAUTIONS FOR ENGINE POWERED WELDERS
Always operate in an open well-ventilated area or vent the engine exhaust directly outdoors.
Never fuel the engine while running or in the presence of an open flame.
Wipe up spilled fuel immediately and wait for fumes to disperse before starting the engine. *Never remove the radiator pressure cap from liquid cooled engines while they are hot to prevent scalding yourself.
Stop the engine before performing any maintenance or trouble shooting. The ignition system should be disabled to prevent accidental start of the engine.
Keep all guards and shields in place.
Keep hands, hair, and clothing away from moving parts.
FIRST AID
The welding area should always be equipped with a fire blanket and a well stocked first aid kit. It is desirable that one person be trained in first aid to treat the minor injuries that may occur. All injuries, no matter how minor they may seem can become more serious if not properly treated by trained medical personnel.
KEY POINTS TO REMEMBER
Be sure the welder is properly installed and grounded.
Never weld without adequate ventilation.
Take proper precautions to prevent fires.
Protect your entire body with fire retardant clothing, shoes, and gloves.
Wear eye protection at all times.
Weld only in a firesafe area.
Never do any welding, cutting, or hot work on used drums, barrels, tanks, or other containers.
Mark metal "HOT" with a soapstone.
Keep a well stocked first aid kit handy.