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Colored iron ore
According to Guangming Daily in March 1982, experts confirmed that Cishan (now Wu 'an, Handan City, Hebei Province) is the birthplace of China compass. That is to say, about 2300 years ago, the natural magnets used by China people to make Sina were mined from here. The main component of natural magnet is ferroferric oxide, which is called magnetite, and it is also the most common type of iron ore in steel production at present. The color of this iron ore is black, which is why people naturally think it is black when they mention iron ore.
But in fact, there are many kinds of iron ore, which can be described as colorful, and because the content (grade) of iron is different from that of iron compounds, it presents different shades and luster colors. In addition to black magnetite, there are cherry red or pig liver red hematite, brown limonite, bright gray ilmenite, blue gray siderite and pyrite that is often mistaken for gold. At present, there are more than 300 kinds of iron ore and iron-bearing minerals found, among which there are more than 70 kinds of/kloc-0. However, under the current technical conditions, few of them have industrial utilization value.
Interestingly, when iron ore is digested by a blast furnace, just like a human stomach, it needs to ensure good air permeability in the furnace, but the difference is that the blast furnace can only eat "coarse grains" but not "flour rice", so the common fine ore in production and trade cannot be directly fed into the furnace, because the fine ore is easy to accumulate in the furnace and has poor air permeability. Besides reducing the melting efficiency and "indigestion" of iron ore, it is more important.
What may surprise you a little is that when the blast furnace "eats" ore, it still has certain requirements on the pH value of iron ore, so according to the pH value of ore, iron ore can be divided into acidic ore and alkaline ore. The selection of acid-base iron ore is related to blast furnace ironmaking index and furnace materials. If the blast furnace uses alkaline slag agent (limestone, for better desulfurization), it is hoped to use alkaline ore; If the blast furnace adopts acid slag agent (quartz stone, in order to improve the utilization coefficient of blast furnace and reduce coke consumption), acid ore should be used.
skill
The raw ore mined from iron ore will contain a certain amount of iron-free or low-iron waste rock, which needs to be crushed, ground and magnetically separated to remove its scum and extract its essence. Therefore, the iron ore often mentioned in the market refers to the screened fine ore or lump ore that meets the requirements of blast furnace granularity.
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China mine is not rich enough.
1960, Tiandu Iron Mine, China's "richest man" so far, has no noise from machines in the past. This century-old mine, located in the northwest of Tiandu Huangniling, Sanya City, Hainan Province, has officially completed its historical mission and closed its pit after vicissitudes. The grade of Tiandu Iron Mine (the percentage of iron in the ore) exceeds 63%, which was once the highest grade and best quality iron ore resource found in China.
Located in the west of Changjiang County, Hainan Province, Shilu Iron Mine is known as "the richest iron mine in Asia". When Qiongya Industrial Bureau 1935 inspected Shiluling Copper Mine, its grade was second only to Tiandu Iron Mine, and its reserve was 65,438+1100 million tons. However, this mine, which had made great contributions to the early iron ore supply in China, basically dried up in August 20 17 and stopped mining. At this point, it can be said that China's rich mineral resources also ended with the end of Shilu Iron Mine, which makes people sigh that there is no stone after Shilu.
The existing iron ore resources in China are generally characterized by "abundant but not rich, miscellaneous but not refined". "Feng" is because China's proven exploitable iron ore reserves reach 23 billion tons, accounting for about 8.3% of the world's exploitable reserves, ranking fifth in the world and not rich; The helplessness of "not being rich" is that about 97% of the reserves are poor, only about 3% are rich, and the national average exploitable grade is less than 30%, and the grade is still declining year by year; "Miscellaneous but not refined" means that most of the existing mineral deposits in China are deeply buried, with complex geological structure and relatively high mining cost. Of the 2,000 iron ore resources that have been proved, only 10 is a large iron ore deposit (> 65.438+100 million tons). Most of the raw ore contains more harmful impurities such as sulfur and phosphorus, and the grade and impurity composition of the raw ore are changeable (see the table below and the figure below).
Global iron ore resources distribution table
Source: World Iron and Steel Association.
Distribution map of iron ore resources in various provinces and cities of China.
Source: Ministry of Land and Resources.
According to the data of the National Bureau of Statistics, the output of raw iron ore in China reached 760 million tons in 20 18, but after calculating the actual pig iron output, the average market grade was only1900,000 tons after screening, and the stripping conversion rate was only about 25%. In 20 18, China's blast furnace swallowed about12.5 billion tons of iron ore. Domestic iron ore was far from satisfying such a high appetite, and China had to rely on a large number of imported iron ore.
skill
The ore containing more than 50% iron is called rich iron ore, and the ore containing less than 50% iron is called lean iron ore.
Think about it.
Why the higher the grade of iron ore, the better?
03
Four families of iron ore
In the history of our country, there used to be "four big families" who controlled the lifeline of the national economy and were prominent for a while. Coincidentally, there are similar "four big families" in the iron ore industry: Vale, RioTinto and BHP Billiton, and the rising star Fortescue. These "four families" control more than half of the world's iron ore supply, and their every move naturally becomes the focus of market attention (see the table below).
Table 20 17 output of four major mines and their proportion in global output
Source: Wind data.
Since ancient times, there has been an allusion that "land occupation is king" in China, and so have the "four iron ore families", which occupy the best iron ore resources of Australia and Brazil, the two countries with the richest iron ore resources in the world. Pilbara is a unique "land king" in Australia, which is divided among Rio Tinto, BHP Billiton and Fortescue. The annual output of iron ore of the three companies here reaches 88% of Australia's total output. The "Tiesijiao" area (quadrilateral area centered on Itabila) and Caragas area are the "land of kings" in Brazil, which are almost monopolized by Vale, and the annual output of Vale alone reaches 85% of Brazil's total output. Coincidentally, these "land kings" are located in the southern hemisphere with little latitude difference, which not only reflects the distribution characteristics of global iron ore "rich in the south and poor in the north", but also has an indissoluble bond with airplanes.
1952 is an epoch-making year in Australian iron ore history. On June 165438+1October16 of this year, Lang Hancock flew over Pilbara, Western Australia, and went to Perth, the capital of Western Australia. When flying over the Hammersley-Lanci Mountains, the sudden storm forced Hancock to fly into a huge canyon. Just as we were crossing the canyon, God's gift came again, this time only to Hancock. The reddish-brown luster on both sides of the gorge wall caught his eye, and he immediately realized that it might be bare iron ore rust. He was flying in a canyon made of iron walls! Soon after, Hancock explored the Hamersley vein with his pocket. After many tests, the grade of iron ore is above 60%, stretching for more than 100 kilometers. The result naturally excited him. In fact, not only Hammersley, but also the whole Pilbara region is the "king's land" of iron ore. The later proven reserves in Pilbara area reached 35 billion tons, accounting for 90% of Australia's total reserves, with an average grade of over 55%.
But Hancock was soon disappointed, because all the experts and the government at that time did not believe that a farmer who had only attended middle school could find such a high-grade super-large rich mine. Because all experts were convinced that Australia is a country with poor iron ore resources, and thought that the iron ore reserves would not exceed 250 million tons, in order to ensure self-sufficiency in the future, the iron ore mining right was strictly controlled at 1938, and the export was prohibited.
Korea never gave up. After eight years' efforts, he finally got the government's franchise to develop the Pilbara area at 1960, and then he struggled to find investors. After hitting the wall countless times, it was not until 1962 that Rio Tinto decided to develop with a grain of salt, which finally brought Rio Tinto an unexpected surprise. After Rio Tinto took the lead, BHP Billiton followed closely and gradually started mining investment in Pilbara.
Also in the "land king" of Pilbara, Fortescue, established in 2003, created a miracle of mining development. In less than five years, it took 10 years to develop large mines. And Fortescue is the first mine in the world to adopt remote control. All mining operation control centers are located in Perth headquarters far from the mining area. The mine is fully automatic, including unmanned trucks, automatic drilling and mining, dehydration telemetry control and so on. It is a modern large mine with the highest production efficiency and the highest production safety factor in the world. Since it was put into production in early 2008, Fortescue, as a "rising star", has quickly ascended the throne of the fourth largest mine in the world. At this point, the pattern of "three points of the world" in the Pilbara area was formed.
It is said that in Brazil, "where there are no trees on the mountain, there will be minerals", which is really reasonable. In the late 1960s, a helicopter of American Steel Company flew in the dense rain forest of Amazon. When it needs to refuel with incidental fuel, it needs to make great efforts to find a bare red clearing in the jungle and land. Geologists on the helicopter were keenly aware that they landed on the iron ore bed and instinctively took samples and brought them back for analysis. They were pleasantly surprised to find that the grade of iron ore was as high as 66%. They stumbled upon another iron mine "King Land", which is the Caragas iron mine area in Pará, northern Brazil, and the largest open-pit iron mine area in the world at present.
The mining right of Karagas iron mine area is not "divided into three" like Pilbara in Australia, but "monopolized" by Vale. Brazil's "Tiesijiao" is an early development area of Vale. With large-scale mining, the best quality hematite gradually decreased, and later the discovery of Caragas became a new territory of Vale. 1970 invested in the construction of Karagas iron mine area, which has been continuously invested and expanded to this day. At present, the annual output has accounted for 50% of the total output of Vale, and it is still the home of the future expansion of iron ore resources in Brazil.
Now, if we want to quantitatively describe the production capacity of these "four families", it can be summed up by "234", that is, the annual production capacity of Fortescue is about 200 million tons, that of Rio Tinto and BHP Billiton is about 300 million tons, and that of Vale is close to 400 million tons. By the end of 20 18, the period of large-scale expansion of the production capacity of the "four big families" has ended. According to the scale of existing projects under construction and the investment period of new projects, at least in the next five years, the global iron ore production capacity will not increase significantly and the total production capacity will enter a relatively stable period.
skill
Australia mainly produces magnetite with stable quality but high water content. Brazil mainly produces hematite with good quality but low hardness.
Think about it.
As a commodity, iron ore should have certain market competition. Do the "four big families" cooperate with each other more or compete more?