Summary of several non-metallic mineral mining technologies

(Suzhou Sinoma Nonmetallic Mineral Industry Design and Research Institute, Suzhou 2 15004)

This paper summarizes the mining technology and practical experience of several important nonmetallic minerals in China, including gypsum, diamond, graphite, bentonite, asbestos, talc, mica and kaolin. This paper briefly analyzes the particularity of these mineral exploitation, and introduces some examples of mineral exploitation technology.

Non-metallic minerals; Mining technology.

About the author: Zhu, a professor-level senior engineer, tel: 0512-68213617, e-mail:.

I. General situation of nonmetallic mineral exploitation

There are 9/kloc-0 nonmetallic minerals with proven resource reserves in China, and more than 20 nonmetallic minerals have been developed on a large scale. At present, only several mining technologies of non-metallic minerals are introduced.

The exploitation of diamonds, kaolin, mica, asbestos, gypsum, graphite, talc and bentonite in China is shown in table 1 [1 ~ 6].

Table 1 Overview of Non-metallic Mining

Note: This table only lists "frequency of occurrence" and does not include company name. 1 carat = 0.2g. 。

Second, the particularity of non-metallic mineral exploitation

(1) mineral grade and crystal protection

Non-metallic minerals have different classification methods according to their uses and industrial requirements, and there are also some special requirements for mining.

As listed in Table 2, minerals such as diamond, asbestos, mica, talc, gypsum, kaolin, etc. In industry, its physical and mechanical properties are mainly or partially utilized to become directly used engineering materials. Diamond particles are fine, so its protection cannot be considered when mining rocks and minerals; When mining diamond placer, due to the high density of diamond, especially the large particles, it is often concentrated at the bottom of sand layer and the lower part of terrace, so special attention should be paid to the protection and mining of this part of ore body. Asbestos, mica, talc, gypsum, kaolin and other minerals should be protected according to industrial requirements.

Table 2 Influence of industrial requirements and classification of nonmetallic mineral products on mining industry

Even if some nonmetallic minerals have the same grade, they contain different grades and different prices, which will cause great changes in mining technical and economic indicators and affect the choice of mining methods. Some are expensive, such as mica ore. The price of a large area of flaky mica reaches 400 yuan/kg, and the price of 4 square centimeters of flaky mica is 80 yuan/kg. From the perspective of economic benefits, crystal protection must be considered when mining.

(2) Occurrence conditions and particularity of occurrence

Such as diamond deposits, the ore body is vertical and tubular. Adaptability should be considered from the selection of development system to mining method.

(3) Characteristics of ores and surrounding rocks

Some nonmetallic minerals and surrounding rocks are soft and thick, so special measures must be taken during mining to ensure the safety and efficiency of production. Such as kaolin and talc, their special properties require corresponding special measures in mining and roadway support. In open-pit mining, because the purer talc is, the better its lubricity is and the natural angle of repose is small, gentle slope is often required, which will increase capital investment and mining cost.

(4) Due to the particularity of ore properties, there are special requirements for mining.

For example, fiber gypsum is expensive, but it is soft and easy to wear, so it needs special protection to prevent wear when mining. Bentonite expands and disintegrates rapidly when it meets water, so wet drilling cannot be used. Kaolin placer contains quartz sand and gravel with loose structure. Kaolin placer is easy to be enriched after washing and elutriation. When mining, hydraulic mining should be adopted to obtain good technical and economic effects.

Third, the general situation of mining various minerals.

(1) gypsum mining

China gypsum deposit belongs to sedimentary type, with large scale and good quality. Underground mining mines include Shaoyang gypsum mine, Pingyi gypsum mine and Taiyuan gypsum mine. The annual output of Nanjing gypsum mine is 40× 104t. Jingmen gypsum mine is currently the largest mine to mine fiber gypsum. Open pit mines are generally small in scale, mainly distributed in Gansu, Sichuan, Ningxia, Qinghai and other provinces.

1. Underground mine development and transportation methods

Its methods include shaft development, such as Pingyi gypsum mine. Inclined shaft development, such as Yingcheng gypsum mine that has been mined; Vertical shaft and inclined shaft are jointly developed, such as Nanjing gypsum mine; Development of adits, such as Taiyuan gypsum mine and Lingshi gypsum mine. Lingshi gypsum mine was once mined by adit chute, but it was unsuccessful. When drawing ore through a large pass, alabaster (gypsum dihydrate with good quality) and ordinary gypsum are easy to be stained with mud and dust, so the ore outlet of the pass is often blocked by water and the production is abnormal. When there is no water, the funnel is full of ore and dust, and the rock dust is fine, which is difficult to be solved by general ventilation measures. Taiyuan gypsum mine adopts adit trackless development, and switched to full trackless mining in the late 1970s and early 1980s, which is the second example of China mining industry at that time, which is both typical and advanced. The advantages of trackless mining in this mine roadway are: the buried depth of ore body is higher than the ground, the seam is gently inclined, and the inclination angle is 5 ~ 10, which is suitable for automobile transportation in roadway development and slicing mining; Using room and pillar mining method, the quasi-cut roadway is basically built in the ore body, which can recover the ore and reduce the capital investment; The stability of ore body and surrounding rock is good, with room height of 10 m and span of 12 ~ 15 m, which is durable and allows the use of large trackless equipment. The roadway section is large, but the actual support rate is only 8%, which saves the capital construction cost; It can be produced at the same time of capital construction and put into production on the spot, which is simple, easy to operate and quick to take effect; The production scale is not large, there are not many transport vehicles in the pit, and ventilation is relatively easy to solve. After the mine was put into production and settled down, the unit investment per ton of mine was only 43.75 yuan, while all mines of the same scale were above 100 yuan in the same period. It shows that this development method is suitable for this kind of gypsum ore body.

2. Gypsum mining technology

Divided into two categories: first, the exploitation of fiber gypsum mine; The second is the exploitation of alabaster, ordinary gypsum and anhydrite. Fiber gypsum has low hardness and high brittleness, and it is easy to be lost as fine ore. In the process of mining and shipping, tamping, harrowing equipment and funnel ore drawing must be avoided. Because of the high value of ore (three times that of ordinary gypsum), longwall separation and filling mining method is adopted, and the ore in top coal caving face is manually separated and loaded into tramcars, such as Jingmen gypsum mine. The mining processes of alabaster, ordinary gypsum and anhydrite are similar, and the whole mining method or room-and-pillar mining method is adopted.

3. Ordinary equipment

The technical equipment in underground mining mainly includes lifting, transportation, air compression, ventilation, drainage, drilling equipment and ore loading equipment. Take only the lifting equipment as an example, as shown below (Table 3). In trackless mining of gypsum mine in Taiyuan, the electric loader with tire, electric scraper with 2 m3 bucket or smaller bucket, dump truck with 10 t mine pit and two 4-72 centrifugal fans are used for ventilation.

Table 3 Examples of underground mining lifting equipment in gypsum mine

(2) Diamond mining

Diamond deposits can be divided into primary and secondary types. The occurrence of primary ore is rock tube type and dike type, and the secondary ore is diamond placer. As far as mining methods are concerned, the rock pipe type is generally open-pit or open-pit underground combined mining. Rock pipe has a special phenomenon, which is an almost upright pipe with a circular or elliptical cross section. Generally, the area is 500~600 m2, and the large area is 2000~3000 m2, and some are even larger. Generally, the depth of rock pipe is getting smaller and smaller, the grade is getting worse and worse, and the quality of diamonds is getting worse and worse (the particle size is getting bigger and bigger). In order to exert the investment effect as soon as possible, the upper part is mined in the open pit. After reaching a certain depth, it will be transferred to underground mining. The primary vein is mined underground, such as Mengyin 1 vein. Secondary diamond placers are all mined in open pit with low grade, but the gem-grade diamond content is high and the economic benefit is good, such as the original Changde diamond mine in Hunan and the original Tancheng diamond mine in Shandong.

1. Develop modes of transportation

Rock pipe open-pit mining adopts highway spiral development, anticlockwise development and 10 t automobile transportation. Diamond placer is generally highway development and automobile transportation.

2. Mining technology

In open-pit mining, bench mining is adopted. YQ- 150A DTH drilling rig is used for drilling, loose blasting, 1 m3 excavator and 10 t truck are used to transport the ore from the working face to the concentrator. The density of diamond is high, reaching 3.52 ~ 3.55g/cm3, mostly concentrated in the bottom of sand layer and the lower part of terrace. Pay attention to cleaning these parts when digging. The suction pipe is also used to clean the floor of coal seam.

(3) Graphite mining

China's crystalline graphite mines are all open-pit mining, including the former Nanshu graphite mine, the former Beishu graphite mine, the Luobei graphite mine in Heilongjiang and the Jixi graphite mine in Heilongjiang. Luobei graphite mine is known as the largest mine in Asia. Cryptomeric graphite mines are all mined underground. At present, there are Jilin Panshi (Yantongshan) graphite mine and Hunan Lutang graphite mine.

1. Develop modes of transportation

Most of the large open-pit mines are developed by roads, with a load of 15 ~ 20 t, and some of them are also transported by 8 t dump trucks. Underground mining, with adits or inclined shaft development.

2. Mining technology

KQ- 150 DTH drilling rig is used for open-pit mining, and 1~2 m3 electric excavator is used for mining and installation. For aphanitic graphite ore mined underground, caving mining method is adopted because of the poor stability of ore and surrounding rock, and because of the lubricity and small friction angle of graphite, the roadway is all inclined, and the pillarless sublevel caving method is creatively adopted. The ore slides from the working face to the ore pass, and part of the enamel pass is set except the slightly inclined roadway, so the whole mining process is not equipped with other loading equipment, which has the advantages of simple equipment, low loading cost and easy mastery.

(4) exploitation of bentonite

Bentonite is a clay mineral with montmorillonite as the main mineral component, also known as montmorillonite clay. Its mining methods include open-pit mining and underground mining, and the annual output of ore exceeds 20× 104t. Open-pit mining includes: Liaoning Heishan bentonite mine, Henan Xinyang bentonite mine, Gansu Jinchang Hongquan bentonite mine, Xinjiang Tuokexun County Cole bentonite mine, Xinjiang Bourcq County Xiazijie mine, etc. Underground mining includes Zhejiang Lin 'an bentonite mine, Zhejiang Qiushan magnetite mine and Jilin Jiutai bentonite mine. Open pit mining accounts for 75% of the total output. There are more than 200 small and medium-sized mines in China.

Open-pit mining generally adopts road development and automobile transportation. Inclined shafts are used to develop underground mines.

Because montmorillonite is an unstable mineral, it will swell violently after absorbing water, which will affect the choice of mining technology. The shallow part of open-pit mining in Heishan bentonite mine is soft bentonite, and the deep part is hard bentonite. Bentonite ore mined underground is usually hard bentonite, while Lin 'an bentonite mine and Qiushan magnetite mine adopt open stope mining method, and Jiutai bentonite mine adopts slicing caving mining method. In mining technology, ordinary wet drilling and water spraying can't be used for dust removal, but electric drills should be used.

(5) Asbestos mining

Asbestos mining methods include open-pit mining and underground mining. At present, all large mines in China are open-pit mining. There are Mangya Asbestos Mine, Bazhou Asbestos Mine in Xinjiang, Ruoqiang Asbestos Mine in Xinjiang and Aksai Asbestos Mine in Gansu. Among them, the concentrate output of Mangya Asbestos Mine is 65,438+00× 65,438+004 t/a, Aksai Asbestos Mine is 20× 65,438+004 t/a and Bazhou Asbestos Mine is 4× 65,438+004 t/a, which are the three largest mining areas in China. The annual output of Aksai Coal Mine is almost 50% of the national total output.

1. Develop modes of transportation

Open pit mines use roads to develop automobile transportation. Due to the increase of the annual total amount of mining and stripping, it reaches (200 ~ 300) × 104t or even more, and the transport vehicles are also developing towards heavy load. At present, 15 t and 20 t dump trucks are usually used.

2. Mining technology

Some large-scale asbestos mines have relatively modern equipment, the mining bench height is 12 m, and the perforating equipment adopts KY- 150 roller drill and YQ- 150 DTH drill. 2 m3 and 4 m3 large excavators have been widely used in mining and loading face to replace small excavators. Auxiliary equipment, such as bulldozers for clearing and leveling sites and collecting ores and rocks, has also been expanded.

(6) talc mining

Large talc mines include Haicheng talc mine in Liaoning, Longsheng talc mine in Guangxi, Pingdu talc mine in Jiaodong, Haiyang talc mine and Qixia talc mine. The output of talc in these three provinces accounts for 85% of the national total output, and they are the three major bases of talc production in China. There are more than 220 talc mines in China, including small and medium-sized mines.

1. Mining method

There are open-pit mining and underground mining. Haicheng talc mine has many open-pit mining sites. It is reported that the total output of concentrate in this area has reached 100× 104t/a, Fanjiabaozi in Haicheng East mining area is the largest open-pit mining talc mine in China, and Longsheng talc mine in Guangxi and Pingdu talc mine in Shandong are sunk open-pit mining. Underground mining includes Haicheng talc mine, Haiyang talc mine and Qixia talc mine in Jiaodong, Shandong Province.

2. Pioneering methods

Open-pit mining makes more use of roads to develop automobile transportation. 7 t and 15 t dump trucks are used for open-pit mining in the east mining area of Haicheng Mine, and 12 t dump trucks are used for transportation in Longsheng Mine of Guangxi. Underground mining: Qixia talc mine and Haiyang talc mine in Jiaodong are developed by shaft; The adit is used to develop the western mining area of Haicheng mine and Haicheng Shuiquan talc mine.

3. Mining technology

The open-pit mine in Haicheng East Mining Area is perforated by YQ- 150A DTH drilling rig and excavated by 1 m3 excavator. Because of the softness of talc, its Mohs hardness is 1 ~ 1.5, which is slippery. Moreover, the higher the purity of talc, the better its lubricity, easy to crack into thin slices, and the natural angle of repose is small, about 35. Surrounding rock is generally unstable, and joints and cracks are developed, which has a great influence on mining technology. For example, the final slope angle of the bottom wall of Haicheng East Open-pit Mine is only 40, and the top wall is 36, which is very slow. The increase in stripping ratio has led to an increase in infrastructure investment and mining costs. In underground mining, roadway support is difficult because of the instability of ore and surrounding rock. Mining in Haixi mining area adopts downward slicing and filling mining method. With the improvement of mineral processing technology, it is allowed to reduce the grade of the selected ore and adopt pillarless sublevel caving mining method for mining. The talc mines in Qixia, Benxi, Shandong and Yingkou, Liaoning adopt sublevel natural caving mining method.

Because talc is mainly used as powder filler in industry, its whiteness is widely used, so it is required not to be dyed by Quaternary soil and dirty water when mining. Hand-picked and directly used in industry should protect the purity.

(7) mica mining

The main muscovite producing areas in China, Altai in Xinjiang, Danba in Sichuan and Tuguiwula in Inner Mongolia, have all been closed. The scale of phlogopite mining is generally small, such as Zhenping, Henan, Ji 'an, Jilin and other places. The broken mica mine is the largest in Lingshou mining area of Hebei province, and there are also some in Jiangxi, Hunan, Hubei and Shanxi. Due to the production and application of mica paper and mica powder, the production of broken mica has occupied the leading position in mica industry.

The open-pit mining of mica includes Altai mica mine in Xinjiang.

Development transportation mode: Open-pit mining generally adopts highway development and slope development, but due to the small mining volume, trenchless development is also adopted. Highway development generally adopts 5t dump trucks for transportation. Trenchless development is to use simple cableway to lift and transport through stope.

Because of the high value of mica ore, small mining scale and simple mining technology, the arrangement of blast holes should avoid the ore-rich zone and be manually selected and transported at the working face after blasting.

(8) Kaolin mining

Kaolin is divided into soft kaolin, sandy kaolin and hard kaolin according to its natural form and industrial requirements. The largest soft kaolin is China Kaolin Company in Suzhou, with an output of 25× 104t/a and high grade. The raw ore can be directly used in industry, and the low grade can be used as refractory. The price of hand-selected 1 mud is more than 10 times higher than that of hand-selected 4 mud. Therefore, it is required to protect high-quality soil, protect the purity of raw ore and prevent it from becoming debris during mining. In the past, manual separation mining was mostly carried out in the mining face, but now the mining scale is large, but in order to connect with the manual separation workshop, appropriate separation mining is still needed. Sandy kaolin (also known as sandy kaolin) is rich in resources in China, which has flourished in the past 10 years and many large and super-large mines have been built. For example, Guangdong Maoming Gaoling Technology Co., Ltd. (10× 104t/a), Guangdong Maoming Petrochemical Kaolin Co., Ltd. (5 ~ 8 )× 104 t/a, and Guangxi Yankuang Group Beihai Kaolin Co., Ltd. (10×/kl Hard kaolin, also known as calcined kaolin, is generally made of coal-series hard kaolin (soil) through deep processing in China. Because hard kaolinite coexists with coal, its mining depends on the mining situation of coal and its own occurrence state.

Kaolin mine has two methods: open-pit mining and underground mining. Generally, hydrothermal altered sedimentary kaolin mines are mined in the shallow part and underground in the deep part. For example, Yangxi Mining Area and Yangdong Mining Area, which belong to Suzhou China Kaolin Company, have been used for shallow open-pit mining. Sandy kaolin is mined in the open pit. Because the ore contains quartz sand or gravel, the structure is loose, and kaolin is easy to be enriched after washing, with good whiteness and fineness. If possible, water mining and water transportation should be adopted. For example, the above two mines in Maoming, Guangdong Province and the mine of Hepu Hutian Kaolin Company in Guangxi under construction. Fujian Longyan Kaolin Company is also sandy kaolin with a large scale. Because of the lack of water there, we can only use the general open-pit mining method, dry mining and dry transportation; Kaolin mine in Beihai Mine of Guangxi Yankuang Group is also dry mining and dry transportation.

1. Develop modes of transportation

Open-pit mining has adopted narrow gauge development, and electric locomotives are used to haul tramcars, such as Yangdong and Yangxi mining areas affiliated to Suzhou China Kaolin Company. When the sandy kaolin is mined by water, the water gun is used for washing and mining, and the mud pump works together. The pulp is transported from the pulp collection pool in the ore block to the concentrator by the pulp pump. Usually, 200/ 150R-AH mud pump is used to transport mud through plastic pipes with a diameter of 250 mm ... Both Longyan Kaolin Mine in Fujian and Beihai Kaolin Mine in Guangxi Yankuang Group adopt road development and automobile transportation. Underground mining includes shaft development and inclined shaft development, such as the mine owned by Suzhou China Kaolin Company.

2. Mining technology

SQ-80, Pinggui-150 and Pinggui -200 water guns are used for hydraulic mining, and the washed pulp is transported to the roughing plant by the slurry pump. The advantages of this mining method are simple process, simple equipment, high labor productivity, advanced pulping process in concentrator and integration of mining and dressing. This method is widely used in Britain. Longyan kaolin mine, like ordinary open pit mines, uses excavators and cars. WK-2 excavator and 17 t dump truck are used in this mine. Underground mining of soft kaolin such as Yangxi vertical shaft and Guanshan vertical shaft in China Kaolin Company is a typical plastic medium because the ore bodies are soft and fragile, plastic, absorbent and expandable when meeting water, and also water-resistant. The closed support is adopted in the vein roadway, and the slicing caving method is adopted in combination with the characteristics of soft and thick ore bodies. When mining, pneumatic picks and hand picks are used to put ore. According to related literature reports, foreign countries adopt scraper-bucket mining-loading combined machinery which can automatically advance along the route for mining. There is pure nitrogen in the marble on the ground, and measures should be taken to prevent nitrogen leakage when the shaft is raised in this rock stratum.

refer to

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Editorial committee of mining manual. Handbook of Mining, Volume IV. Beijing: Metallurgical Industry Press, 1990.

Editorial committee of nonmetallic mineral industry handbook. Handbook of nonmetallic mineral industry (I and II). Beijing: Metallurgical Industry Press, 1992.

[4] Zhu Zhu. Discussion on non-metallic mining industry's response to WTO. China Building Materials, 2002(6)

[5] Tang Jingyan, He. Present situation of development and utilization of nonmetallic minerals in China. China Building Materials, 2006 (1)

Hu Qin, Zhou Wei. On the development strategy of nonmetallic mineral industry in China. China nonmetallic mineral industry guide, 2008 (1)

Brief introduction of several non-metallic mineral mining technologies in China

bright red

(Cai Zhong Design and Research Institute of Nonmetallic Minerals, Suzhou, Jiangsu 2 15004)

Abstract: The mining technology and practical experience of several nonmetallic minerals such as gypsum, diamond, graphite, bentonite, asbestos, talc, mica and kaolin in China are summarized. The mining technical characteristics of these minerals are briefly analyzed. Some mining examples are introduced.

Key words: nonmetallic minerals, mining technology.