This standard only considers the process loss of electrolytic copper, road loss is not included.
(1) Process loss
Copper loss in slag is the main loss in copper smelting. According to the loss form, it can be divided into three types:
① Chemical loss
It refers to the loss caused by copper slagging in the form of Cu2O. As long as there is enough sulfur in the charge, Cu2O will become sulfide. But if the sulfur is insufficient or the oxidation atmosphere is too large, and there is not enough reaction conditions, the slag containing Cu2O pair may be higher.
② Physical loss
It refers to the loss of copper dissolved in slag in the form of Cu2S. It depends on the composition of slag, acid slag dissolved less, high FeO content of slag on Cu2S solubility is large, therefore, in order to reduce the physical loss of copper, should be as far as possible to reduce the amount of FeO in slag, or improve the acidity, or add CaO instead of part of FeO.
③ Mechanical loss
It is caused by failure of matte particles to be removed from slag. Slag viscosity and specific gravity is too large, melting point is too high to make the matte is not easy to clear; The slag superheat is not enough, the volume and shape of molten pool are unreasonable, and the settling time is not guaranteed. Incomplete chemical reactions, resulting in the floating of bubbles; The matte particles are too small to combine into large particles. In addition, the emission of flue gas and electrolyte will cause the loss of copper.
Metal loss in copper smelting process:
① The metal recovery rate of blast furnace smelting process is 97.8%, and the metal loss is 2.2%;
(2) The metal recovery rate of converter blowing process is 99.5%, and the metal loss accounts for 0.5% of the amount of metal in the process.
(3) The metal recovery rate of anode furnace scouring process is 99.5%, and the metal loss accounts for 0.5% of the metal input process.
(4) The metal recovery rate of copper electrolysis process is 99%, and the metal loss accounts for 1% of the amount of metal in the process.
The total recovery rate of copper smelting is 96.0% and the metal loss is 4.0%, according to the calculation of the metal recovery rate of the above processes.
2 normal loss
The loss of concentrates in transportation and storage is more complex. Generally, it can be carried out according to the following provisions, but in this standard, the travel loss will not be included.
① The concentrate is loaded after landing at the port, and the cargo loss is calculated as 0.1%. If the concentrate is loaded after 5 days, the cargo loss will increase by 0.01% for each additional day.
② concentrate after landing, each inverted time, the loss of 0.1%.
③ In the process of train transportation, cargo damage is calculated at 0.3%-0.4%, and it increases by 0.1% for every 100 km when the transportation distance exceeds 500 km.
Due to the influence of external factors, cargo damage sometimes increases. The heavy rain for more than 2 hours increases the cargo damage by 0.05; Under moderate rain for more than 4 hours continuous cargo damage plus 0.05%; More than 8 hours of light rain, cargo damage plus 0.05%. After the landing of the goods, due to heavy wind damage, should be based on the actual situation to collect evidence (site record, photo, video, etc.) to determine.
⑤ The storage loss of concentrate after entering the plant (including the loss outside the warehouse, the loss of unloading, the loss of storage and transportation in the warehouse) is calculated as 0.3%.