One article to understand imported copper ore and its concentrates
Metal copper, element symbol Cu, atomic weight 63.54, specific gravity 8.92, melting point 1083°C. Pure copper is light rose or light red in color. After a copper oxide film is formed on the surface, the appearance becomes purple-red, so it is often called red copper. Copper is a typical sulfur-loving element. It mainly forms sulfides in nature. It only forms oxides under strong oxidizing conditions. Natural copper can be formed under reducing conditions.
At present, more than 250 kinds of copper minerals and copper-containing minerals have been discovered in the earth's crust, mainly sulfides and similar compounds, copper oxides, natural copper, and copper sulfates, carbonates, and silicates. Class minerals.
From the perspective of regional distribution, there are five regions with the richest copper reserves in the world: the western foothills of the Andes in Peru and Chile in South America; the Luoji and Daping Valley areas in the west of the United States; Congo and Zambia in Africa; the Republic of Kazakhstan; eastern Canada and middle part. From the perspective of country distribution, the world's copper resources are mainly concentrated in Chile, the United States, Zambia, the CIS and Peru. Chile is the country with the richest copper resources in the world, and its copper metal reserves account for about 1/4 of the world's total reserves.
--Distribution of global copper reserves
Although my country is known as a country with large copper resources, its natural endowment of copper resources is poor and there are many defects: such as small deposit scale, many poor ores, few rich ores, many associated ores, and few single copper mines. In general, my country's copper resources are relatively poor in both quantity and grade, with low international competitiveness and insufficient copper resources, especially copper-rich resources. At present, my country's imported copper concentrate accounts for about 75% of the overall demand.
--Geographical distribution of copper mines in my country
Copper smelting process
The development of copper smelting technology has gone through a long process, but so far copper smelting is still dominated by fire smelting, whose output accounts for about 85% of the world's total copper output.
Fire smelting
--pyromethod smelting plant
Fire refining is to produce cathode copper, that is, electrolytic copper, through melting refining and electrolytic refining. It is generally suitable for high-grade copper sulfide ores.
The pyrometallurgical smelting process is short and adaptable, and the copper recovery rate can reach 95%. However, because the sulfur in the ore is discharged as sulfur dioxide waste gas in the two stages of matte making and blowing, it is difficult to recover and easily causes pollution.
--Hydro-smelting plant
Generally suitable for low-grade copper oxide, the refined copper produced is called electrolytic copper.
Copper ore international trade pricing mechanism
Copper ore is one of the bulk materials in international trade. Our country is a copper-deficient country and needs to import a large amount of copper ore every year to meet domestic needs. The main factor affecting the price of copper concentrate is the change in supply and demand. From a commodity perspective, the main factors are copper content, precious metal content, harmful elements, and impurity content. From the perspective of the pricing mechanism, it is closely related to the level of processing fees negotiated between the buyer and the seller and the choice of the pricing period.
At present, my country's imported copper concentrates are mainly priced according to formulas, and some companies have signed fixed-price contracts with sellers, but fixed-price contracts are not the mainstream pricing method. In international trade, the prices of copper, gold and silver in copper concentrates are often calculated using the transaction prices of copper, gold and silver published in the Metal Bulletin (METAL BULLETIN) published by the London Hardware Exchange (LME).
Formula pricing The pricing formula for imported copper concentrate is usually: basic price per dry ton of copper concentrate = (copper content - loss) * London copper price during the pricing period - processing fee + (gold content * recovery rate) * London gold price - processing fee + (silver content * recovery rate) * London silver price - processing fee will be deducted for harmful elements if the processing fee exceeds the standard.
In addition, some small and medium-sized enterprises or trading enterprises adopt the pricing coefficient method to price imported copper concentrate, that is, the price of imported copper concentrate = copper content * LME copper price in the pricing period * pricing coefficient. However, whether it is pricing by deducting processing fees or pricing coefficients, when the quality and other aspects of the signing date are not much different, the prices derived from the two pricing methods should be basically close.
