The feasibility report on the expansion of the EOB was submitted by MRDL to SML in February 2022. Recently, based upon the exploration data of 2021 The mineable ore reserves were further increased to 115 million tons @ 0.374% Cu, further 23 shallow drill holes of 100m each and 20 deep drill holes of 300-400m each drilled up to the end of 2021, as per initial reports the mineable ore reserves increased up to 119 million tons @0.374 Cu but the detailed report is still awaited.
Post-Expansion Scenario
According to the Expansion Feasibility Report of EOB submitted in February 2022 based on the exploration data of 2019, the total amount of ore-bearing rocks within the pit limit is 215.36 million tons out of which the ore is 115.04 million and 100.31 million tons are waste rock with an average stripping ratio of 0.87t/t. The post-expansion production capacity for mining and mineral processing will be 21,200 t/d (700×104t/a) producing 110,000 t/a copper concentrate @ 22.5% Cu and the smelting capacity will reach to 24,276 t/a of blister copper.
Beneficiation Expansion
The capacity of the existing process plant is 425×104 t/a and the capacity of the new concentrator to be installed will be 275×104 t/a. The 425×104 t/a concentrate in the existing concentrator and the 275×104 t/a concentrate in the new concentrator (700×104 t/a in total) will be thickened and dehydrated together utilizing the existing workshops. There are two flotation tanks available in the existing system which are enough to be used for the processing of the increased production. However, a concentrate dehydration filter press will be added to the existing workshop based on the total ore processed i.e. 700×104 t/a.
Existing & Expansion Tailings Facility
As per the final feasibility of the east ore body, the total tailings amount is 8968.9×104t and the tailings accumulation volume is 6406.4×104m3.
The Xigou TSF is the current tailing storage facility in use that is about 2km to the east of the concentrator with a total capacity is about 8823.82×104m3.
As per the expansion beneficiation project (700×104 t/a), the total tailings produced quantity will be 113 million tons @ 20500 t/d. The Xigou TSF will be used as a tailings dam for the coming 2 to 3 years. According to MRDL, the construction of a new Chagou TSF is proposed in the adjacent valley on the west side of Xigou TSF which is inevitable and will be constructed in the meantime, after the finalization of the expansion of EOB whose tentative completion time is 18 months with the storage capacity of 4988.47x104m3. Both of these TSFs will be used one after another as far as the tailings pond scheme is concerned.
Expansion in Utilities/Powerhouse
Water Supply: The current water supply is from the underground water sources 40 km away and 8 deep wells are used to collect water from a depth of about 200m underground. In the proposed design, the operation mode of the main pump of the primary pump station of the existing water source will be changed from the current two-use & two-standby mode to a three-use and one-standby mode and the daily water transport capacity will be increased to 27,234m3 to meet the overall water demand of the project.
Power House: Considering that the existing power generation units have been in operation for about 100,000 hours and the production demand for the following years will not be met due to the limitation of the unit status and service life of the generating units.
The current power/energy requirement is 27MW for 425×104t/a production which is met from the 05 heavy oil generating units provided in a centralized way with 03 for operation and 02 miscellaneous with 01 at overhauling and 01 for standby/backup.
The power/energy requirement will be 14MW for the expanded capacity of 275×104t/a, therefore 02 additional heavy oil generating units will be installed at the reserved location making the total number of generating units to 07 with 05 for operation, 01 for standby/backup and 01 at overhauling producing the overall output power of 41MW that will meet the power demand of the project.