Simply put, iron ore is an iron-containing mineral with economic value, and the main minerals with industrial value are magnetite, hematite, limonite and siderite. The molecular formula, theoretical iron content, density, color, strength and reducibility of each mineral are summarized as follows. It should be noted that limonite is a series of hematite with crystal water, with up to 6 kinds. The mineral with the highest iron content is magnetite, which is 72.4%Fe, so the iron content of all iron ore products is lower than this figure, generally between 58% and 65%, and the rest is impurities.
Iron content and characteristics of typical iron ore minerals
2. The commodity of iron ore is always related to the particle size of the ore. How to divide it?
In the process of steelmaking, the particle size and porosity of iron ore have great influence on the smelting process of blast furnace.
If the particle size is too small, it will affect the permeability of the material column in the blast furnace and increase the gas rising resistance.
Excessive particle size will affect the heating of burden and the reduction process of ore. Because of the large particle size, the contact area between gas and ore is reduced, and the central part of ore is not easy to be reduced, thus reducing the reduction speed and improving the coke ratio.
Therefore, iron ore products first look at iron content, and then look at particle size. In industry, we classify iron ore according to the following grades:
1) coarse powder: the particle size distribution is basically 0- 10 mm, in which the particle size above 10 mm generally does not exceed 10%, and the maximum particle size below 0. 15 mm does not exceed 35%.
2) Fine powder: basically made in China, less than 200 mesh (0.074mm). Generally, foreign minerals used in China are coarse powders, but now they also use imported fine powders, such as Russian fine powders, Ukrainian fine powders and Brazilian SSFT powders. The refined powder should be not less than 70% and less than 0.074 mm.
3) Block ore: There are two kinds, one is standard block with particle size of 6-40mm. The other is the mixed block, which generally needs to be screened and broken before it can be used.
4) Raw ore: The raw ore is collected from the mine without mineral processing or other technical treatment, but the particle size of the raw ore is preferably not more than 300 mm.. A few raw ores can be used directly, and most of them can be used only after mineral processing or other technical treatment. In mineral processing, the ore that enters the separation operation after grinding is called clean raw ore.
5) fineore: fine ore mines in English; Smalls has a lower grade than lump ore, and it may be necessary to turn the lump ore into fine ore through crushing, grinding, separation and other steps to meet the grade requirements, generally 60-67%, and there are also iron ore commodities with a grade of 57%.
3. Typical chemical analysis data parameters and price relationship of mainstream iron ore products in China market.
Although we know the iron content and particle size of iron ore, there are still strict requirements for the content of silicon, aluminum and phosphorus in the ore. At the same time, because most limonite ores contain different degrees of crystal water, the loss on ignition (LOI) of the ore is also a key data of the product. The following table is some analysis values of mainstream iron ore in the current market for reference.
Typical chemical analysis values of imported iron ore in China iron ore market
Relationship between iron content of various products in iron ore market and SiO _ 2+Al _ 2O _ 3.
The relative price of iron ore products can be seen from the following table. PB powder is the standard, others are at premium unit price, for example, super-special powder is reduced by 90 RMB per ton. In addition, the reward and punishment system of each variety is also included in the table below.
Deliverable brands and brand promotion and discounts of large trading companies.
Iron ore impurity reward and punishment system table
4. Classification and source of mainstream minerals in China market:
We can classify the iron ore produced by the four major mines with the largest annual output introduced in this series of articles, and the corresponding distribution of their source mines is as follows.
A. Riotinto
Distribution map of Rio Tinto's main ores
Relationship diagram of Rio Tinto's main ore products and their source mines and ports
(1)PB powder and block (PilbaraFines；; PilbaraLumps), also known as Pilbara mixed ore.
PB powder and lump are the most mainstream minerals in the world, which are used by almost all large steel mills. PB powder is also a template ore of Platts index, and its price is generally higher than the index 1 USD.
Rio Tinto's PilbaraBlend product is the most recognized iron ore brand in the world, which is famous for its high quality and consistency. Rio Tinto's PilbaraBlend products account for about 70% of Rio Tinto's iron ore product portfolio. It is also the largest and most liquid iron ore on the market today, and is called "the dollar in iron ore". Rio Tinto's high-grade ore also helps to reduce greenhouse gas and other air emissions, and its fluidity and stable quality make it the first choice for China's steel industry.
The grade of lead powder is about 665438 0.5%, and some limonite has good sintering performance. The lumpiness is about 62.5%, which belongs to limonite with good reducibility and average thermal strength.
Lead powder (PBF) and lead block (PBL) can be made from powder ore of 12 mine, such as Bai Zixuan mine, Palabudu mine, Malandu mine, Brookman mine, nnamdi mine and Xi 'an Angelas mine. The corresponding ports and ore sources are shown in the above figure.
(2)Roberivervalleyfines/RoberivervalleyLumps。
Rob river powder and lumps are produced in Rio Tinto's MesaJ and MesaA mines in Australia; The grade is about 56.9%, which belongs to limonite, with low iron grade, high SiO2 _ 2 and Al _ 2O _ 3 content and large burning loss, but the price is relatively cheap. Luobuhe ore powder contains 3%-5% rehydration, which will lead to high fuel rate and low productivity; The sintering performance is not good, but the smelting performance of its sinter is good. The corresponding ports and mines are shown above.
(3) Nicotinamide adenine nucleoside
Rio Tinto Yangdi Powder (Yang Di) contains 57.3% iron and low impurities, so it can produce high-iron sinter. Customers in East Asia and South China use it as the basic raw material of sintering mixture. At present, BHP Billiton's Yangdi Powder (Little Yang Di) market is relatively liquid. Generally speaking, we are familiar with BHP Billiton's Little Yang Di.
B. BHP Billiton
Distribution map of main mines in BHP
(1) Newman fine ore and lump ore (Newman fine ore/Newman lump ore)
Newman fine ore and lump ore are located in Newman Mountain Mine in East Pilbara, Australia, which belongs to hematite and has good sintering performance. The powder grade is about 62.7%, and the block grade is about 65%.
Newman powder has good sintering performance, which can improve sinter strength and reduce fuel consumption. The chemical composition of Newman powder is relatively stable, with low silica and few trace elements, but high alumina and phosphorus content. Generally, it needs to be matched with low aluminum varieties, such as PB powder, Mike powder, Ba coarse and so on. So Newman powder is not suitable for steel mills that produce cast pipes.
(2) MacFines
The grade of Mike powder is about 665,438+0.3%, which is about 58% in China market at present. Part of it belongs to limonite, which has good sintering performance, contains about 5% crystal water, and has high burning loss during ironmaking. With the increase of its proportion, the sintering rate of sinter decreases gradually. According to the research of steel works, when the proportion of Mike powder is 15%-20%, the grade of sinter less than 5mm is low, and the sintering yield is the highest when the proportion is 20%.
(3) Small Yang Di powder
Small Yang Di powder has a grade of about 57.3%, low aluminum content, low content of other harmful elements, stable composition and small fluctuation. It is a low-aluminum variety in Australian ore series, belonging to limonite with high crystallization water and high water demand for mixture. Because of its loose structure, good sintering assimilation and reactivity, it can partially replace Newman Mountain fine ore or Brazilian fine ore, and the ratio is 10, which is widely used by steel mills. The content of Al2O3 is relatively low, and both kinds of mineral powder are coarser than those in Hammersley. They all have reasonable smelting performance, but poor sintering performance.
(4) Ba Fen, kimble
Jinbuba powder belongs to intermediate Australian limonite, with iron content of 6 1%, phosphorus content of iron ore of 0.02% and high Al2O3 content of about 2.6%.
Jinbuba powder, like most limonite, has good liquid phase generation ability, which is beneficial to improve sintering permeability and sintering output. However, a large proportion of Kimbuba powder affects the sintering strength and increases the consumption of solid fuel. The proportion of Jinbuba powder used in steel mills is generally controlled at 10-20%. Many steel mills are worried about its high phosphorus content, so it is difficult to increase the proportion, especially those that smelt varieties of steel or cast pipe factories.
C.FMG iron ore products
Before 20 13, the varieties of FMG were mainly rocket powder, rocket special powder and super special powder. After 20 14, FMG mixed rocket powder and ultra-special powder for sale, which is called mixed powder, ultra-special or mainstream, and the amount is particularly large, which is the mainstream of low-grade ore. There are only four levels of products defined by FMG: Super Classical, Fortescuebland, Kings and WPF(WestPilbaraFines). These product names are quite confusing in the domestic market, so we include them here.
(1)FMG mixed powder (FortescureBlendFines)
FMG mixed powder belongs to low-grade Australian limonite, and its composition is relatively stable. The typical iron grade is 58.3%, the aluminum content is as high as that of most Australian ores, reaching 2.5%, and the manganese content is slightly higher (0.57%), but the trace elements such as phosphorus are relatively low.
FMG mixed powder has low assimilation temperature, good liquid fluidity and good air permeability, which can improve the sinter yield. However, the large proportion of sinter will affect the strength of sinter and increase fuel consumption. If it is mixed with low aluminum Brazilian powder or refined powder, it is beneficial to the quality of sinter. The proportion of steel mills ranges from 10-30%, and some steel mills reach 40%.
(2) Super professional essence
Ultra-fine powder belongs to low-grade Australian limonite, with iron content of 56.7%, high aluminum and manganese content and relatively low phosphorus content, and the ignition loss is generally 8.5-9.5%. It is a kind of iron ore with high burning loss, which can improve the sintering permeability, but also increase the consumption of sintering solid fuel, and other trace elements are low.
The proportion of steel mills is 10-30%, and the proportion of steel mills that use ultrafine powder for a long time is controlled at around 20%. Steel mills generally use low-grade varieties such as FMG mixed powder and Yangdi powder instead, and steel mills use ultra-special powder to react with Brazilian powder or refined powder to ensure the quality of sinter.
(3) Rocket powder, also known as FMG powder, is the name that the company no longer uses?
Produced by FMG company; According to market legend, it was once used as a component of rocket engine fuel, so it was called rocket powder. Its grade is about 58.5%, silicon is about 4, and aluminum is about 1.5. It belongs to limonite, with good sintering performance, large reserves, high grade of single firing and crystal water of about 8%. The chemical composition of FMG powder ore is better than that of yandi powder, but its sintering performance and pelletizing performance are not as good as that of yandi powder.
(4) rocket powder, now it should be KingsFine.
Rocket powder with a grade of about 57.5% produced by FMG Company contains about 5 silicon and 2 aluminum, and its other smelting properties are the same as those of rocket powder. The grade of super special powder is lower than that of rocket special powder (1), about 56.5%, about 6 for silicon, about 3 for aluminum, and about 8.5% for crystal water. Other smelting properties are similar.
(5) Sipilbara powder (WPF), a new brand used by the company.
D. FOY-F of Roy Mountain Iron Mine
Royce Hill's product index and pricing model are similar to Rio Tinto's PB series products. Although the water content of fine ore is relatively large, the grade of fine ore is about 6 1% and the phosphorus content is as low as 0.04%, which is more advantageous than the existing mainstream intermediate fine ore in Australia.
Compared with fine ore, the market acceptance of Luoshan lump ore is higher, the powder rate of Luoshan lump ore is lower than PB, and the iron grade of Luoshan fine ore is lower than PB. Although product positioning can replace PB powder, steel mills have recently paid more attention to the grade of iron.
E.Atlas powder block:
The iron ore produced by AtlasIron Company of Pilbara Mine in Australia belongs to limonite with a grade of 57.5%, crystal water of about 9% and high silicon content of about 8%. Its physical and chemical properties and smelting properties are similar to those of ultrafine rocket powder.
F: Brazilian iron ore, mainly from Vale.
(1) card powder (SFCJ powder)
Caragas powder is abbreviated as SFCJ powder, which is SINTERFEEDCarajas. The iron content is above 65% (65-67%) and the silicon content is 1%-2%. Aluminum is about 1%, phosphorus is about 0.033-0.045%, burning loss is about 1.6%, and moisture is about 8-9%. The iron ore produced by Caragas mine in Brazil is very popular in the international market, and its price is higher than that of the southern mine source, because the fine ore there is of high quality.
Harmful elements are also relatively low, which is conducive to improving sinter grade, providing conditions for adding low-quality iron ore, and is also suitable for steel mills with high logistics costs. Silicon dioxide is low, which can be matched with low-priced and high-silicon varieties to reduce the cost of ore blending and flux consumption. However, due to the low silicon content, the single sintering effect is not very good, which leads to poor liquid production effect and affects the strength and sintering output when participating in framing.
Basica powder is more expensive, so it is of little significance to increase the proportion after the steel profit is reduced.
(2) Brazilian coarse powder
There are many varieties of Brazilian coarse flour, mainly Vale South flour and CSN Brazil flour. Brazil coarse powder has a common feature, which is basically hematite, with relatively low S, P and Al2O3, especially with extremely low harmful elements such as S, so it is suitable for varieties with high trace elements. In recent years, the quality has seriously declined, and the silicon and aluminum are getting higher and higher.
The proportion of steel mills is generally between 10-30%, and the combination of Brazilian coarse powder and iron ore with high fire damage is beneficial to improve the quality of sinter.
(3) Brazilian refined powder
Brazil's refined flour grade is relatively high, basically around 65%, and the harmful elements are extremely low, which is suitable for low-quality non-mainstream goods with high harmful elements.
Because it is between pellet powder and sintered powder, Brazilian refined powder is flaky, with poor water absorption, high melting point, unsatisfactory assimilation and liquid phase fluidity, and it is necessary to increase fuel consumption, but the sinter strength is better.
(4)CSN powder and block:
The iron ore produced by Brazilian CSN Company (full name is Brazilian state-owned ferrous metal company) contains more than 65% iron and 1%-2% silicon.
(5)SSFT powder:
The iron content of SSFT is about 65% and the silicon content is about 4.4% in the sintering powder specially made by Brazil's Vale Company for China market.
(6) Southern Brazil powder:
The mine is located in Brazil, and the south source is "Iron Corner", also known as Brazilian South Powder. The main mines in the southern mining area are Itabira, Mariana, MihasCentrals, ParaopeBAl, VarGEmGrande and Itabiritos, all of which are located in the four corners of Brazilian iron ore. The main mining method in southern mining area is open pit mining. This area is dominated by felsic with high hematite content and iron content of about 66%. It mainly includes SSFG powder (standard sintering powder in southern Brazil, iron grade 65%, silicon 3.2-3.8%, aluminum 1.2- 1.8%, phosphorus 0.049-0.065%, manganese 0.25-0.40% and water 6.5-8.5%.
(7) baruch:
Refers to Brazilian coarse-grained fine ore, which is the general name of Brazilian coarse powder, including kafen, SSFT powder, CSN powder, southern powder and so on. The grade varies from 65% to 58%, and the smelting performance of the mineral powder produced by Southeast Tiejiao is the best.
G. Indian iron ore and Indian powder
There are many kinds of Indian flour. Generally speaking, Indian powder belongs to hematite, with high aluminum and manganese content and moderate crystal water content. At present, the typical components of Indian powder on the market are 57.5% iron, 5.5% silicon, 4.5% aluminum, 0.05% phosphorus, 0.03% sulfur, 1 1% moisture.
The main purpose of using Indian powder in steel mills is to reduce the cost of hot metal. In the case of high profits of steel mills, medium and low-grade Indian powder is used less; On the contrary, when the profit is low, the use of middle and low-grade Indian powder will increase. The proportion of Indian powder used by steel mills ranges from 5% to 20%.