shock! This is the most terrible place for steel mill pollution!

Over the years, China's annual output of steel at a speed of one hundred million tons every two years soared: in 2005 the annual output of 350 million tons, to 800 million tons in 2014 became, much of the new steel plant in the south of Yanshan Tangshan area.

Tens of millions of tons of ore are sent to steel mills hundreds of kilometers a year. Ore beneficiation plant will smash screening, to single out the highest grade of ore carried away, the rest of the "tailings" poured into the deserted valley.

The surrounding farmers have also earned a steady income from the mines and bought more consumer goods. The riverside ditch in the village is full of plastic bags for various commodities.

Rural garbage bag

This kind of wealth and environmental destruction coexist, so I have been full of curiosity about the steel plant in the south of Yanshan.

On the eve of Earth Day this year, I drove from the south to the north and traversed the northern steel base centered on Tangshan, and had a deeper understanding of resources and environmental issues.

Mountain iron ore

Industrial waste has become a problem that Chinese society cannot bypass

Since 2010, when I discussed the Chinese economy, I often heard a joke that was not fabricated.

World steel production ranking:

First place: China (excluding Hebei Province);

Second place: Hebei Province, China (excluding Tangshan City);

Third place: Tangshan City, Hebei Province, China (excluding the output of the newspaper);

Fourth place: Japan

Fifth place: United States

Sixth place: India

Seventh place: Russia

Eighth place: South Korea

Ninth place: the reported output of Tangshan City, Hebei Province, China;

Tenth place: ...

This time I crossed the towns around Tangshan, I first saw a few spontaneously formed recycled rubber industry belts – too many trucks for the steel industry, just normal tire replacement is enough to feed dozens of rubber processing plants.

Recycled rubber

Going inside, just a small township and town dare to call themselves "China" or even the "world" the largest XX steel base.

But to my surprise, these township environments that can influence the global market in a certain segment are quite good. Steel mills and rolling mills stand in the green fields, only a touch of smoke, most of the dust is still from the trucks on the road. .

However, from Tangshan to the north, entering the hilly area outside Yanshan, the situation is completely different.

In some places, over the ridges, you can see the clouds that cover the sky. The chimneys of the steel mills are full of smoke. The roads must be repeatedly sprinkled with water to make the industrial smoke and dust interfere with traffic. The factory waste piles are rolled up with black dust. So that the hills that are a little further away can't see the outline. Most of the pedestrians on the road carry masks, and I can only close the windows.

Steel plant

Slightly low visibility

Going to the mountains, the mining site has not simply modified the outline of the mountain, and often the entire mountain has become a mine. The huge tailings dam was connected from one hill to the other and turned into part of the mountain.

Of course, the so-called "tailings", in fact, were originally part of the mountain. They only walked together with the iron powder that was sent away in the ore dressing equipment, were mechanically ground, and added many mineral processing drugs.

In fact, if you can cleanse the harmful drugs, carefully avoid the tailings powder and precipitation mixed with debris flow, many tailings are not more terrible than rocks and sand, but can be used very much.

In some places in Tangshan, tailings were evenly deposited on fields with insufficient soil, planting trees on them, and gradually transforming them into fertile land.

But another metallurgical waste - Smoke is not so easy to deal with.

The tailings have only undergone beneficiation, have not been smelted, have not been reduced to various metals at high temperatures, and are essentially ground stones. Soot (such as blast furnace gas ash) with all the selected ore into the high temperature furnace, with high temperature gas is discharged outside the furnace, which contains a variety of metals, whether it is scattered into the air, or collected Stacking may release heavy metals to air, groundwater, and soil.

Soot accumulation

Soot accumulation, more shocking at the back

A little check on the information, I found that my "common sense" significantly underestimated the number of metallurgical soot:

The annual smoke entering the metallurgical chimney has reached the order of 40 million tons, which is equivalent to the total production of Chinese metal in the year I was born (1981).

Therefore, the treatment of metallurgical soot can significantly affect the environmental effects of the metallurgical industry, and even determine whether the entire metallurgical industry can continue to operate.

Stacking like a mountain, this angle is more shocking

As early as a decade ago, some experts noticed

Heavy metal pollution in the metallurgical industry

Wang Dongyan, an expert at Shanghai Baosteel Research Institute, said:

"The more a country's output of iron and steel plant dust containing zinc, indicating the popularity of the country's automobile consumption, but it also shows that the greater the zinc pollution prevention and control of pressure and responsibility."

According to the data provided by experts, the zinc content in the dust of China's steel mills has reached 3% to 5%, and the rate of increase is very fast.

This is related to the rapid development of China's auto industry. The zinc content in the dust of steel mills in some developed countries is as high as 20%.

According to environmental experts, a large amount of zinc-containing dust, if not handled properly, can cause serious environmental pollution. If it is under the action of rain, heavy metal zinc will penetrate into the ground and pollute the groundwater source.

Zinc-containing dust is thinner than flour, and open-air stacking will fly in the air, causing respiratory diseases such as heat fainting.

In addition, valuable elements such as zinc, lead , iron and carbon in zinc-containing dusts will not be used effectively, and will also result in waste of resources.

Experts say that the most important part of preventing zinc pollution in automobiles is the steel plant.

According to the survey, the annual incidence of dust containing zinc in China's steel plants is as high as 2.8 million tons:

“If steel mills are to achieve sustainable development, it is impossible to pay attention to the development of zinc-containing dust treatment technology”.

According to Wang Dongyan, an expert at Baosteel, China's steel plants are still lagging behind in dust treatment.

As the most modern steel enterprise in China, Baosteel accounts for about 150,000 to 200,000 tons of zinc dust per year. However, only half of it is currently used in the sintering machine, and the other half separates high-zinc substances by simple physical methods. These high-zinc substances are also difficult to use effectively.

Fourteen years have passed, China's steel output has increased by three or four times, and automobile production has increased by six or seven times. It is conceivable that the potential hazards of metallurgical soot have also increased several times.

In fact, significant heavy metal pollution belts have formed around heavy industry cities.

However, China's metallurgical soot problem has unique characteristics. Most of China's steel comes from iron ore. It must undergo the steps of iron oxide reduction ironmaking. Therefore, a large amount of heavy metal fumes will be produced in the iron making process. Western countries have accumulated enough steel in industry and life, and the annual elimination of scrap is enough to provide most of the steelmaking raw materials, only to reduce the shortage of iron ore to supplement scrap.

Therefore, China will generate more iron-smelting fumes and put more pressure on the soot processing industry. If it is not handled properly, it can be directly landfilled or used as building materials. As long as there is water soaking, a large amount of heavy metals will dissolve and pollute fresh water resources and soil.

Smoke pile that invades the river

Map of soil zinc pollution in suburbs of Shenyang

Can only move forward

Regardless of the potential threat of metallurgical waste, it is impossible for China to simply abandon or compress the scale of the metallurgical industry.

The reason is simple - our metal is not enough.

China’s total steelmaking in the past few decades has just surpassed the three countries of the United States, Japan and Germany, but China’s total population is more than twice that of the three countries, which means

China's per capita steel accumulation in production/life (more than 5 tons) is less than half that of developed countries (at least ten tons).

Considering that a significant amount of steel in China has become an export commodity, the actual ratio may be lower.

This is also why most developed countries can mainly use scrap steel to recycle steel. We must also mine iron ore for iron mining.

Forecast results of crude steel consumption in major regions of the world

Obviously, the Chinese cannot tolerate the stagnation of economic growth. We need more metal equipment to improve production efficiency, and we need more metal durable goods to improve the quality of life. Any policy that prevents Chinese people's living standards from continuing to catch up with developed countries is reasonable, and then "justice" cannot be implemented.

From the field trip, it is true that townships and towns of steel plants will have better infrastructure, such as kindergarten/school/village activity centers.

Village activity center and middle school

Therefore, the only way out for China is to continue to refine steel and metallurgy. Otherwise, not only the country will not be able to make progress, but even the ecology of the steel producing areas will not be preserved. The precipitation in the Yanshan area near Tangshan is very small. The result of the return of residents to agriculture is drought. The sloping agriculture in the area destroyed the vegetation and turned Yanshan into Guangshan Baling.

Fragile vegetation, unable to withstand agricultural development

Fortunately, the problem of metallurgical soot is also a huge asset - its toxicity also means a very high metal content. After all, it has also undergone the refining and metallurgical furnace refining, which is more worthy of "extracting" than ordinary ore. Useful ingredients.

Still take zinc as an example.

30% of the world's metal zinc comes from industrial wastes such as metallurgical soot, which is only 18% in China, while Chinese industry consumes nearly half of the world's zinc. Considering that the world's proven reserves of zinc mines can only support less than a generation, steel-rich soot rich in zinc is a non-disposable treasure.

As for the mobile phone screen and the metal indium necessary for almost all liquid crystal displays, there is no independent mineral deposit in the world, and it must be extracted from associated metals such as tin zinc. Metallurgical soot is often enriched in indium and is an important source of extraction.

China's metallurgical soot recycling still has a lot of room for development

There are also many iron elements in the metallurgical soot. In addition to directly returning to the furnace to continue ironmaking, it can also produce a good direct reduced iron powder, an important raw material for powder metallurgy.

The so-called powder metallurgy is to put the metal powder into the mold and sinter like ceramic to form a part with much higher performance than mechanical processing. Brake pads for cars and high-speed trains, transmission gears for transmissions, are now often made with powder metallurgy and work well.

At present, the content of powder metallurgy parts of each car is 8.7 kg in Japan, 19.5 kg in North America, and only 6 kg in China. One of the bottlenecks restricting the development of China's powder metallurgy is the direct reduction of iron powder production – domestic demand of 18 million tons per year and production of only 1 million tons.

The extraction of direct reduced iron from metallurgical soot is also an important means to reduce pollution and promote industrial upgrading.

Powder metallurgy

Powder metallurgy parts

In short, metallurgical soot is on the one hand limiting the development of China's metallurgical industry, and on the other hand is an undoubted development opportunity. Large-scale/intensive soot recycling treatment can create space for the metallurgical industry, and also bring new opportunities to China in terms of resources/industry upgrades.

TUBING

Tubing is mainly used to provide oil and gas flow passage during production of oil and gas wells. For flowing wells, due to the large inner diameter of the CASING, the casing is directly used for production. Due to the density difference, pressure drop and expansion, the liquid flows up rapidly, causing the liquid to slip, resulting in the ineffective utilization of the downhole elastic energy. Running tubing with smaller OD and ID during production can effectively solve the above problems by allowing fluid to flow in the tubing. Therefore, running tubing is required during production of flowing wells. The downhole operation and production of flowing well and non flowing well can be completed by using various tools for tubing running.