Mining Activities In The Open Mine

Open pit is an excavation carried out on the surface of land that is intended to take the materials in the ore minerals in the soil surface. Surface mining is one of two known mining systems, namely the open mines and underground mines. where all the activities or mining activities conducted on or relatively near the earth's surface and the workplace is directly related to the outside world.

Mining the open pit itself is done with several stages of the process of work which includes:

• The Preparation Stage 
• Mining Operations  
• Processing and Marketing 
• Reclamation

* The Preparation Stage

In the preparatory phase of mining activity performed early in the process of extraction or mining of minerals consists of the preparation phase or pre-mining process, and in this activity include: 

1. Making Cross-Roads At The Mining Area

This passage serves as a heavy equipment transport to the mine site, and then developed as a haul road from the front material mining to crushing plant site. Road construction machinery Bulldozer uses which can be also functioned as a means of stripping overburden. 
  
2. Land Clearing Mining Area 

This work was done before the stage of overburden stripping the upper metallic minerals. These activities include cutting and gathering of trees that grow on the surface area to be mined and the purpose of this activity to clean up the mine area so that mining activities can be done easily without having to interfere with the disruption of existing vegetation in the area of mining  

3. Stripping The Cover

Overburden disposal is intended to clean the limestone deposits that will be extracted from all kinds of impurities that covers a surface, so it will facilitate the work of excavation in addition to the results would be relatively more effective in the net in the processing of minerals Over burden in the project area consists of two types of top soil and overburden so that the coating layer made ​​of a layer of top soil in advance and placed in a particular area for future reclamation purposes.After the top soil layer peeling, then performed on a layer of overburden stripping and then pushed and placed on certain areas and some roads are used as hardener. Stripping activities carried out in stages by using a bulldozer, where the initial stages of stripping done to prepare the first step and subsequent stripping can be done simultaneously with the production phase, so the pattern is applied and the parallel series which aims to: 

• Saving investments and the cost of preparation. 
• Avoid contamination of the limestone deposits cover layer, thus simplifying the work of excavation. 
• Avoid the occurrence of avalanches and wind hazards.

4. Preparation Of Mining Equipment

Mining will be done focussed by using mechanical equipment. The tool used is required to support mining activities, namely:

• Bulldozer, used for land clearing and overburden stripping. 
• Loader, which is used to load chunks of limestone, the result of the demolition and above conveyance. 
• Truck, which is used as a conveyance of the mining front to the mill crushing / grinding. 
• Crushing Plant, which is a processing unit that serves as a preparation tool mining limestone from the front in order to obtain the desired grain size by the market. 
• Power Plant, serves as a source of electricity that will be used as lighting, for the processing tool and move the tool - a tool that works in the factory. 
• Water pumps, used to pump or draw water to meet the needs of equipment and employees.

5. Preparation Of Mineral Ore Crushing Plant Material
 

Crushing mill is used as a place of crushing the ore mineral material that has been in the mines and this should be made large enough to accommodate the material mined

a. Site Selection crushing and Stock Pile

Based on the topography of the site selection is usually a slightly sloping area. Plant site selected areas which are relatively flat and without vegetation so it only needs to process or work only as needed flattening. and close to existing infrastructure such as roads, and lighting. 

b. Installation of Equipment at Factory crusher
Crusher machine is required for placement of foundation that is strong enough to survive long enough to be held in accordance with the project

c. Location of Offices
The ingredients used as the central office organization and conduct of mining activities and planned work is in the region are easily accessible and close to the entrance. The building was made permanent as it is used in a very long period of time in accordance with the project's life. 

d. Equipment Maintenance Center
In the smooth operation of the equipment required is always in good condition and ready to use. For that much needed a facility as a place of treatment equipment (spare parts), so that treatment of equipment or machines that can be done routinely used both in the types of treatment are mild and replacement parts.

e. Lighting
Facility lighting is intended to provide lighting around the buildings, roads, and particularly in employment support activities. Power source for lighting does not become one with electricity for the plant, so special for this lighting facilities required a generator. 

f. Source Of Water
Water is the source of the means which are vital to a project that involves a lot of manpower. Besides the water is used as daily necessities, water is also used in mining activities obtained from groundwater by drilling. g. Other Supporting Infrastructure
The meaning here is the other infrastructure facilities used for public purposes other than for use by the company which can also be used by local communities so as to have a positive impact on people's lives around. Other infrastructure includes sports advice, suggestions of places of worship, clinics, power house, and security posts  

* Mining Operations

The main objective of the mining activities are taking deposits of parent rock, making it easy to be transported and processed within the next process further. After preparation of the mining operation is completed and stripping overburden at the top of the limestone reserves realized (the direction of mining progress from top to bottom contour). Then it can begin mining operations.

Mining activities are divided into three activities, namely the dismantling, loading and transportation. The details of these three activities are:

1. Demolition

Demolition is an activity to separate the precipitate with host rock minerals performed after stripping the overburden sediments lime stones is completed. Demolition can be carried out by using blasting, mechanical equipment and non-mechanical equipment.For demolition activities lime stones using drilling and blasting done. after the rocks were blown up and then demolished using bulldozers, which is then collected at the edge of the mine or mines each side of the road block. Many lime stones are dismantled each block are not the same, depending on the quality requirements demanded by consumers. 

2. Loading 

Loading is the work being done to include or fill material or mineral deposits results in the dismantling conveyances. Loading activities performed after the eviction activities, loading and unloading is done by using a Wheel Loader and loaded into the conveyance. Loading activities aiming to move into the lime stones of dismantling conveyances. Freight carried by the system cycle, meaning that the truck had been loaded straight off without having to wait for another truck and then unload directly back to the mine site to be loaded again. 

3. Transport
Freight is the work being done to transport or carry materials or deposits of minerals from the mining front was taken to the processing for further processing. Dump Truck transport activity using a then taken to the place of processing to do the process of crushing (crushing), the number of trucks that will be used depending on the number of blasting limestone material to be transported.

  

*Processing And Marketing  

1. Processing
Is an activity which aims to increase levels or enhance the quality of minerals produced from the mine to meet the requirements to be traded or used as feedstock for other industrial materials. Minerals produced from the mines contain valuable minerals usually in addition to the desired also contain mineral impurities (gangue minerals) so that the mine can not be directly exploited or trafficked. To remove mineral impurities so that the mine can be used or traded, then performed with the processing of minerals (ore / mineral dressing). The process of separating valuable minerals separation between the impurity minerals based on differences in physical and chemical properties of precious minerals with minerals impurities. Another advantage of the processing of minerals in addition to increasing levels of quality. Is also to reduce the amount of volume and weight so as to reduce the amount of volume and weight so as to reduce its transportation costs.

2. marketing
Marketing is an activity that aims to sell a product to the user or consumer product with a predetermined price or based on agreement between both parties concerned. Marketing activities carried out after processing or after the conditions have been determined by the consumer against product quality are met.

* Reclamation
Reclamation is a work that aims to repair or restore the living environment to be more efficient. This effort must be made every businessman (entrepreneur mining) according to the applicable government regulations.

In practice there are some difficulties for the reclamation of mined area is without a good management plan. The difficulties include:

• Not doing so the observation of soil humus in the implementation of wasted a lot of soil humus. 
• Not done thoroughly so that there is a former mining area that was left open for a while because there is some soil excavation remaining.
• The difficulty of determining the landfill cover soil.    

Some important factors that interplay between the environment of other mining activities application of mining technology. Activity of these factors affect each other not only on the outside of the mining environment where carrying capacity is reduced, but the mining operations will experience obstacles in the smooth operation. Reclamation of mined area is done by taking back the land cover (top soil) to the former mining area was then performed for fertilizing soil restore stability and soil fertility. So it can be planted with plants that are more productive for the local population, so that environmental governance is not much different from the previous environment