1. Dust Control
In general, aerodynamic dimensions (sizes) of dust formed in mine operations have rather less in sizes and emission (atmosphere-released levels). Therefore, the area of effect that may occur because of mine operation is narrow. Dust emissions in this narrow effect area can have impact on vegetation and agriculture around the mine. Therefore, dust that may be formed in mine operations has been constantly kept under control using various control methods and its effects to the environment have been sighted by the means of modelling and measuring.
Koza Gold Operations complies with the emission limit values as specified in the Air Quality Protection Regulation, and the Regulation for the Protection of Industrial-sourced Air Quality. In order to achieve this, Particles substance and settled dust measures have been regularly conducted for PM emission control within EIA Undertakings. Particle substance concentration 10 pm and under are being checked hourly by automatic beta-ray type measuring device. For settled dust, dust buckets are used in measuring monthly. Additionally, watering method is being used to reduce PM emissions that may occur at open pit before or after blasting at open pit.
Water spraying has been also used to suppress potential particle substances at ore discharge point situated in crushing unit. Furthermore; there is dust holding unit at the mill’s crushing area. By employing these control methods, exceeding of the limit values of particle substance emissions as defined by the regulations can be prevented. Measuring results are being regularly reported each month to Provincial Department of Environment and Urban Affairs and Special Province Administration of Izmir.
2. Hydrogen Cyanide (HCN) Gas Control
In order to prevent formation of HCN gas that may result due to environment Ph from process sources like leaching, settling and desorption units and to maintain gold/silver recovery percentage in best optimum level, pH is kept at above 10. For safe working environment, HCN gas formation is prevented and continuous HCN measures are taken around these units. There are three HCN gas measuring detectors at the mine site. One of these devices is installed on leach tanks able to measure and other two have been portable and ready to be installed on appropriate places to be able to conduct measuring around plant and tailing pond as to be determined by Inspection and Monitoring Committee. There are two staged alarm limits being 5 ppm and 10 ppm. Measuring results are being regularly reported each month to Provincial Department of Environment and Urban Affairs and Special Province Administration of Izmir
3. Noise Control
Koza Gold Operations Inc. complies with the Regulation for Managing and Assessing Environmental Noise. Noise value limits are measured automatically day and night at 1 meter distance from dwellings in the closest residential areas to mine site.
Measuring results are being regularly reported each month to Provincial Department of Environment and Urban Affairs and Special Province Administration of Izmir.
4. Importation, Transportation, Storage and Handling of Chemical Materials:
Koza Gold Operations A.S. complies and shall continue to comply with the various provisions of the regulations set for packaging and labelling, storing, transporting and use of the Cyanide:
- Sodium cyanide tank is fire and moisture resistant construction. It is surrounded by fence and storage and fence gate is kept locked. Dry powder extinguishers are used against fire.
- The units which contain cyanide and packaging are labelled in compliance with relevant procedures and international standards
- Steel tanks were constructed for processing ore with sodium cyanide. These tanks are situated at concrete units on inclined floor, surrounded by high steps and equipped with pump. If there is discharge to concrete unit for any reason pump is activated and slurry/water system is feed backed.
Lime: Lime used for basic at the plant is stored in 35 tones confined silo and pulse-jet bag filtering system provides dust controlling.
Hydrochloric Acid is transported to the mine site by tankers and stored in 30m3 fibres glass or rubber covered steel tank.
Caustic Soda is transported to the mine site by tankers and stored in 30m3 steel tanks.
Precipitant is supplied in bags and stocked in storage.
Active Carbon is supplied in bags and stocked in storage.
SO2: stored in tanks in comply with the standards of TSI 1519.
There are safety showers to be used by plant employees in certain sections of the plant.
The explosives are brought into the mine site on a daily basis by authorized explosive company permitted to transport such materials. Noise and vibration measurements are conducted by automatic blasting measuring devices set up 1 meter away from dwellings in settlement units. Noise and vibration values resulting from blasting are recorded by the use of these devices and the results regularly are reported each month to Provincial Department of Environment and Urban Affairs and Special Province Administration of Izmir.
6. Plant Wastes
Koza Gold Operations A.S. has established a chemical decomposition plant to decompose the tailing formed therein. This plant consists of:-
1. – Cyanide Destruction by INCO SO2/air Process
2.- Heavy metal Stabilization by Ferric Sulphate process,
3.- Hypochlorite Decomposition for spoilage in the plant and cyanide
The controls are conducted at three points:
- Chemical decomposition unit outlet: Before being discharged to the pond, slurry taken daily from a spot is sampled and cyanide is analysed. The results are being reported to the relevant authorities on daily, weekly and monthly basis.
- Water fed to the plant from pond has been sampled every day at the point where water runs into feeding tower and analysed. Results are being reported to the relevant authorities on daily, weekly and monthly basis.
- Daily sampling is conducted on the present water in tailing pond and arsenic antimony is analysed. Furthermore, heavy metal concentrations are analysed once a week. The results are being reported to the relevant authorities on daily, weekly and monthly basis.
7. Storing of Tailing
Koza Gold Operations Inc. stores chemically decomposed tailing at tailing pond (TSF). Tailing dam (TSF) project was approved by State Hydraulic Works Authority (DSI) and it was constructed in conformity with protocol and technical specification signed with DSI and under the supervision of State Hydraulic Works Authority.
- Inner surface of the pond is spread from bottom upwards HDPE geomembrane impervious composite layer
- A retaining structure project was prepared using stripped material in front of the main embankment for increased stability of the tailing pond.
- Tailing dam was constructed in conformity with Disaster Management Regulations and State hydraulic Works dam safety co-efficiencies enduring seismicity in the area.
- There is filtering layer in which draining pipes on impervious clay layer. The water in the tailing is drained a collected at water collection tank in pond and is pumped back to plant for re-use.
- No waste discharge has been and will be made from pond to receiving environment.
- The surrounding of tailing dam was effectively drained thus water resulting from rain was stopped overflowing directly into the tailing pond.
- The pipes carrying plant waste were installed in a PVC pipe which is 25% larger in dimension. All tanks and pipes containing cyanide have been tested every day to ensure that there are no leakages.
- Tailing storage plant has been managed within the framework of “Tailing Storage Management Plan” submitted to the Ministry of Environment and Urban Affairs.
8. Monitoring Underground Water
Observation boreholes were drilled at the mine sites along the fences surrounding the mine sites, which represent to be best spot on the side of downstream of the TSF within the main embankment slope, at the direction of underground water flow. The mouths of boreholes have been isolated and locked to prevent surface water running into and boreholes are surrounded by fence for safety reasons. All boreholes have been installed with pumping settings. These boreholes were set up on the basis of holding all types of polluted underground water likely to originate from the plant and be pumped back there. During the operational stage, samples have been periodically taken in these wells and analysis results have been reported to official authorities on monthly and quarterly basis…
9. Control of Water inrush from Underground Operations
As underground mine is below surface water level, there have been water drainages to underground from cracks and fault zones during underground operations. Part of the excess water from underground and open pit is used in spraying for dust control. Remaining water is kept in tanks and discharged into creek based on discharge permission after ensuring receiving environment standards are achieved. The water is sampled daily to check pH and Suspension solid substances. Additionally, weekly composite sampling has been analysed and the results are reported to official authorities on a monthly basis.
10. Meteorological Measurements
As required by the General Directorate of Meteorology, automatic meteorology stations were set up at some operations to determine meteorological data and to measure temperature, rainfall, direction and speed of the wind, humidity, and air pressure. The results are reported monthly to official authorities.