In recent years, we established our Environmental Conservation Program with policies to support ecosystems and maintain the sustainability of natural resources. Being mindful of how our operations center on natural resource utilization, we apply the principles of "Green Mining" to be environmentally conscious, taking care to minimize any disturbance to the balance and function of nature around us. In 2019, we set success indicators for our program to protect and preserve the living environment, using them as a guide to realizing our program objectives. These indicators, as updated in 2020, are illustrated below
We have realized that climate change is one of the most severe problems facing this era. The previous generation did not have the technology; the next generation does not have the time, so it is up to us to take this responsibility and make a change.
CITA is located in remote area and no access to electricity, therefore electricity generated by generator using fossil fuel. Electricity used mainly for camp facilities and washing plant. Fuel consumption is also used for trucks, light vehicle, and heavy equipment (dozer and excavator) with control by records the use of fuel. CITA its also installed solar power plants to help reduce the need of fossil fuel generation for energy production.
There are two major types of mining waste at CITA. The first is a result of the mining activity itself, referred to as overburden (OB) or waste rock. The most critical aspect of handling this material would be ensuring OB placed properly, geo-technically stable and control mine water. Bauxite mine materials are not generating acid water but need to control for reducing total suspended sediment (tss) and dissolved metal. Mineout as well as OB will properly closed by managing slope, soil coverage and revegetation (see reclamation)
The other major important waste is bauxite residue in the form of ore washing sludge, which has a solids composition of around 40% of the processed tonnage from the bauxite deposit, or 10,000 to 30,000 tons per day, mixed with 40,000 m3/day of water. This residue flows into a sediment pond and settles.
This creates a series of sedimentation ponds within the vicinity. Each pond that has reached its maximum holding capacity is closed and revegetated according to company plan.
Bauxite residue produced by the alumina refinery process is classified as hazardous waste due to additives (mainly sodium hydroxide or caustic soda) that raise the pH (alkalinity) of the bauxite residue to highly corrosive levels. This particular byproduct is regarded as red mud or tailings.
The hazardous waste landfill facility Class II-type created to hold red mud and coal ash was built with geotextile drainage layers and geomembrane barriers as a secure landfill. Ministry of Environmental and Forestry granted landfill permit operation for WHW in 2016 and expansion landfill is in progress for 2021.
The "dry stacking" and landfill disposal method applied is far superior in environmental safety to the wet disposal methods (red mud/tailings dam/ash lagoon) traditionally used for these wastes.
Mining Ore Washing Plant
Recycle water used in washing plant coming from series of sediment ponds which incorporates as circular (closed-loop) water system. Overflow water that has been separated and cleaned from residue in the sediment pond is returned to the reservoir to be reused for washing. This allows us to conserve water as much as possible. Additional water pumped from river as make up water especially during dry season (evaporation higher than rainfall).
Alumina Water Use
The alumina refinery has a relatively higher water consumption mainly for Processing Plant, power plant and domestic usage. Water source coming from river and rainfall water collector. Reuse and recycle are implemented in the WHW mainly at processing plan using redmud waste filtered press water.