Indonesia - Limestone Investment Analysis and Crushing Process
Indonesia is the largest country in ASEAN with a land area of 1.919 million square kilometers and a marine area of 3.16 million square kilometers. The mineral resources are very rich in Indonesia, especially the limestone resource.
Limestone mine has broad prospects for investment
In recent years, the limestone mining industry in Indonesia has risen greatly, which not only drives the economic development of Indonesia, but also provides a large number of job opportunities, and brought huge business opportunities for the limestone crushing industry.
The specific reasons are as follows:
1. Indonesian limestone mineral resources are abundant
Indonesia's limestone reserves are about 34 billion tons, and proven reserves are about 28 billion tons, mainly distributed in the south and north of West Java, East Java, Papua in the east, Bali and Sumatra. It is the main non-metallic mine in Indonesia and ranks second after the coal mine.
Limestone mineral resource
2. The support of government policy
On December 16, 2008, the Indonesian Parliament passed the new mining law. On January 12, 2009, the Indonesian President issued a new law No. 4 to replace Act No. 11 of 1967, which was implemented in the country for 41 years.
The most essential reform of the new mining law is that it replaces the long-term implementation of the Contract of Work (COW) and the coal mining enterprise work permit system (PKP2B) in Indonesia with a new licensing system.
In order to attract more funds to its domestic mining sector, currently, Indonesia government is launching a series of attractive policies and constantly revising and improving mining investment laws.
3. Huge demand of the infrastructure needs
The relatively lagging development of infrastructure construction in Indonesia is a major bottleneck restricting Indonesia's economic growth and investment environment.
At the same time, strengthening infrastructure construction is also an important factor in ensuring that the Indonesian economy can grow at an average annual rate of 6%. At present, the construction industry is Indonesia's second largest industry whose output value accounts for about 10% of GDP. The average growth rate had reached 7% between 2009 and 2013, which is the main driving force for Indonesia's economic growth.
The infrastructure is also the main part of the construction industry. The output value of infrastructure construction in 2013 accounted for 53.8% of the total output value of the construction industry.
Therefore, Indonesian governments have made infrastructure construction a priority for government investment. As the basic raw material for the production of cement, the limestone is only increasing in demand.
Large return on investment (%)
|State||Return Industry return||Risk National return||Overall ratio Average weight||Market risk||National risk||Average weight||Ratio|
Source: Business Monitor International（BMI）
The Asia-Pacific mining risk return rankings published by Business Monitor International show that Indonesia and Australia rank first and second in the Asia-Pacific region with their rich mineral resources and stable investment environment.
Other major mining countries in the Asia-Pacific region are slightly inferior due to their respective shortcomings. This shows that Indonesia is becoming a leading mining leader in Asia.
The physical properties of limestone are small hardness and high brittleness with low silicon content and low abrasiveness. Therefore, the limestone is relatively easy to crush with low production cost.
According to different uses, limestone needs to be crushed into particles of different sizes: the products of 20-50mm size are mainly used for burning lime and the products of -20mm size can be ground into different meshes to meet the needs of various industries such as power plants.
The classification of finished limestone
This requires understanding the basic process of limestone crushing
1. Analysis of limestone raw materials
Limestone is mined by blasting. Due to the blasting distance and other reasons, the particle size of the raw materials varies, and during the mining and transportation process, the the soil and other debris are included.
Due to the above reasons and considering the optimization of the process, the main problems to be considered in the limestone crushing process and design process are:
- During the crushing process, the mud removal process is considered according to the quantity of the mud content;
- The change of the particle size of the raw material is relatively large, so the selection of the feeding size of the crushing equipment needs to have a margin;
- Since the main finished product is used to burn lime, in order to ensure the maximum content of 20-50mm grain-level finished products, it is necessary to prevent repeated and excessive crushing, and the crushing equipment should preferentially be selected with small crushing ratio.
- Recovering a part of fine limestone powder by using dust removal equipment to reduce the dust;
- The selection of crushing, sieving and dust removal equipment should be properly larger than design to prevent fluctuations of raw materials;
- The crushing process realizes a closed loop.
2. Process analysis under different crusher configurations
Based on the limestone crushing design requirements, the following crushing options are available:
- 1Feeder +jaw crusher + fine jaw crusher + vibrating screen
- 2Feeder + jaw crusher + impact crusher + vibrating screen
- 3Feeder + jaw crusher + cone crusher + vibrating screen
- 4Feeder + jaw crusher + hammer crusher + vibrating screen
- 5Feeder + heavy hammer crusher + vibrating screen
Limestone crushing solutions
3. The advantages of the above schemes are analyzed as follows
- The total capacity of the crushing and screening equipment of 1 is 120KW. It has the advantages of good stability, low failure rate and simple operation, low replacement frequency of wearing parts and high discharge rate of finished products (20-50mm).
- The total capacity of the crushing and screening equipment of 2 is 191 KW. Its advantage are that the crushing ratio is large and the maintenance is simple. However, for the process requirements, the content of the discharging below 20 mm is relatively high.
- The total capacity of the crushing and screening equipment of 3 is 156KW. Its advantage are that the operation is simple and the wear resistance of the wearing parts is good, but compared with 1, the equipment cost is high.
- The total capacity of the crushing and screening equipment of 4 is 171KW, and the equipment advantage is the same as that of 2, but the stability and the replacement frequency of wearing parts are high, thus the production and maintenance cost is high.
- The total capacity of the crushing and screening equipment of 5 is 136KW. The advantages of the equipment lie in the simple process, convenient operation and high degree of humanization, but the content of -20mm is high.
In summary, considering the advantages and disadvantages of several crushing methods, plus the physical properties of limestone, and to meet the maximum size of 20-50mm grain products, equipment with a relatively small crushing ratio should be selected. Thus, priority is given to the jaw crusher.
The initial plan is to use two-stage jaw crushers. The size of the discharge port of a section of jaw crusher can be adjusted larger slightly. After the crushing, the grade of +50mm is sent into the second-stage jaw crusher to reduce the fine powder. The two-stage crushers achieve a closed loop.
The crushing process
The limestone production line is a common production line in the heavy industry equipment, which is favored and chosen by many customers. The common limestone crushing production line includes vibrating feeder, jaw crusher, belt conveyor and vibrating screen.
Limestone production line with a capacity of 100 t/h
The raw materials are transported from the warehouse through the ESW380×95 vibrating feeder (-3mm purlin, adjustable). The waste is transported through the belt under the screen; the material above the screen is fed into the PE500×750 jaw crusher, then transported into 4YK1848 vibrating screen for sieving;
The materials of -20 mm is stored in the transfer silo and the qualified product of 20-50 mm are transported by the conveyor to the finished silo;
The limestone of +50 mm is returned to PEX250×1200 jaw crusher for further crushing and then enters the 4YK1848 vibrating screen through the conveyor (both sections are closed loop systems).
The crushing and screening system in the process is equipped with a pulse dust collector (quantity, model, etc. are chosen according to site conditions).
The process of limestone crushing
|Vibrating feeder||ZSW380×95||1||With sieving|
|Jaw crusher||PE500×750||1||Primary crushing|
|Jaw crusher||PEX250×1200||1||Primary crushing|
|Vibrating screen||4YK1848||1||Screening material|
Optimization of equipment configuration
- 1After the crushing, the 20-50 mm product is 1800 t/d, and the material entering the crushing equipment is expected to be 2000t/h (working time is 20 h/d, and capacity is 100t/h). Considering that the limestone is easily crushed with larger finished size requirements, the PE500×750 jaw crusher (maximum treatment is about 80-90t/h) can be selected;
- 2Because of the blasting, the maximum feed size (425mm) of the PE500×750 jaw crusher may not be large enough for feeding materials, so it is necessary to ensure that the material size is smaller than the maximum feed size of the jaw crusher.
- 3If there has too many mud in the raw material, a soil removal screen should be added.
Indonesia's unique natural resources have brought unlimited business opportunities to the limestone mining industry, and the demand for crushing equipment is increasing. Investors can get a good crushing effect by adopting the appropriate process configuration and equipment selection. In combination with the principle of “breaking more and less grinding” in the limestone production line, it is necessary to produce the best particle size in the stage of crushing limestone.
Henan Fote Heavy Machinery specializes in the production of mining equipment for 40 years. It has rich crushing experiences in the production of limestone mining equipment with advanced crushing technology and complete after-sales service, and is favored by domestic and foreign customers.
The company will continue to adhere to the “focus on the best crusher” concept, and continue to provide the best material crushing solutions and quality services.
Fote Heavy Machinery(FTM)