MINING STUDY
MINING STUDY
MINING STUDY
It should be noted that in accordance with mining standards, only the resources indicated were used in this study.
Note that the exploration distinguished three mineralized zones Naindan 1, Soso Town 3 and Soso 2.
6.1 MINERAL RESERVES
6.1.1 Introduction
Optimization of the geological resources of NLMC Mining deposits was carried out with the Lerchs-Grossman algorithm on NPV
Mining costs and processing costs for optimization were calculated and estimated based on figures similar to those practiced in Liberia. A price of 1,500 USD/Oz and a rate of 264,000 t/year were considered.
- Mine Copper, Gold and Silve
- Type Open Pit and Underground Mine
- Ownership 80% Gold Mining
Optimization
The optimization of the resources of the Soso Town – Soso deposits was carried out with the Lerchs-Grossman algorithm of the Whittle software, version 4X-V3.1 which gives the possibility of outputting either in the form of tables (.CSV) or in the form pit shells in closed Polylines (String) in addition to the following technical elements:
• The marginal cut-off grade;
• Tonnage by rock type (ore or waste);
• The stripping ratio, tonne of waste: tonne of ore;
• The gold content;
• The metal contained;
• Operating costs by type and nature;
• Initial investment or replacement costs;
• The undiscounted cash of the pit;
• The net present value of the pit;
• The investment return period;
Page 3 sur 269
• The lifespan of the deposit for each production rate;
The schudeler VPV tool allows optimization to be carried out in two steps:
• The first step consists of generating all the possible pits by varying the price of gold from a minimum value (in general it is the price which does not give any pits) to a maximum value (the price which allows to have all the resources inside the pit). The pits thus generated are nested. In the case of Soso Town – Soso, prices varied from $1,200/Oz to $1,500/Oz.
• The second step consists of making an economic evaluation of each pit, generated in the first step, with a single price which is the trend one. The trend price used in the case of Soso Town – Soso is $1,500/Oz. This step, with an analysis of the tonnage, stripping ratio, metal and cash flow curves, makes it possible to choose the optimal pit corresponding to the pit maximizing cash flow.
The 3D Mine Blocks model
As the geological model block only consists of mineralized blocks, it will be necessary to add the waste blocks to obtain the Mine model block necessary for optimization. The characteristics of each barren block to be added depend on its location and the properties of the facies in which this block is found.
• The model Mine block was built based on the following data: Import of the geological block model, the surfaces between the different facies, the topographic surface;
• Creation of the sterile & air model block;
• Integration of boundaries between different types of rocks: boundary surface between laterite, Saprolite, and altered Saprock and finally fresh rock;
• Development of the mine model which is the addition of the geological model block + sterile model + optimization parameters file.
Resource optimization was done on the mine block model thus developed in Datamine and exported to NPV.
Furthermore, the optimization block contains the following parameters:
• The coordinates of the block centers
• The width, length and height of each block
• The geological content in place of each block
• The density of each block
• Rock type: rock type is the code assigned by rock type
• Saprolite ore of indicated category
• Saprock ore of indicated category
• Saprolite ore of inferred category
• Inferred category saprock ore
• Healthy rock ore of inferred category
Page 5 sur 269
• The lateritic waste
• The Saprolite barren
Conformément aux standards miniers, l’optimisation n’a porté que sur les ressources indiquées, les ressources inférées sont considérées comme stérile à valeur nulle.
6.1.5.1 Optimization parameters
Techno-economic parameters
The mining costs considered are those of subcontracted exploitation and the estimate is made according to the analysis of several proposals from subcontractors for exploitation in similar areas and who have considerable experience in West Africa. . Mining costs assume a diesel price of $0.85/l and assume that no use of explosives will be necessary as all mining will take place in weathered areas. Additional mining costs have been included for contract supervision and administration, as well as ore grade control and dewatering. General and administrative (G&A) costs of $1.5/t of ore It is important to note that the costs used for pit optimization are preliminary estimates for developing the economic limits of the pit and may be slightly different from the operating costs later developed in the Business Plan.
Dewatering
Since the piezometric level in the area and in the vicinity of the area planned for exploitation is approximately 100m and since the depth of the pits will rarely exceed this depth, the dewatering will be sized only to dry up the rainwater.
Geotechnical parameters
The objective of the geotechnical parameters is the study of the stability of the pit and its dependencies, for this the following parameters will be defined initially from the study of similar cases in Liberia which we had the opportunity to to work Analyze the stability of the pit: On the scale of the slaughter bench o On the scale of the ultimate bench o On the scale of the inter-ramp o On the scale of the pit. • Define the pit design parameters: o The height of the step o The angle of the slope o The orientation of the sides of the pit. o The width of the berms o Rolling ramp: width, slope and recommended positioning in relation to the sides of the pit o Drainage system: Recommendations to follow to drain rainwater and/or water ingress to safeguard the stability of the pit on its sides during Operation. • Define the design parameters of the heap: o Recommended choice of location for the dump o The height of the level o The slope of the level of the level o The width of the berm o The width of the rolling ramp o Slope of the ramp o Drainage system
Material properties
Since the piezometric level in the area and in the vicinity of the area planned for exploitation is approximately 100m and since the depth of the pits will rarely exceed this depth, the dewatering will be sized only to dry up the rainwater.
Density
The density considered in this study is 2 t/m3.
Overgrowth factor
The expansion factor reflects the increase in volume of material from its in situ state after excavation. The expansion factor is an important parameter used to determine requirements for loading and transportation equipment, as well as dump and storage designs. An expansion factor of 30% was used. Once the rock is placed in the stockpile, the expansion factor will be reduced to 10% due to compaction by truck and bull.
The NLMC deposits are made up of 3 pits:
• Soso Town 03: this is the main pit which contains the majority of reserves 1,465,000 t at 1.16 g/t giving an in situ metal of 1,699 kg. It extends over a length of approximately 660m, a width of 220 and a depth of 120m • Soso Town 01: this is the second pit which contains 357,000 t at 1.03 g/t for 367 kg of gold. Dimensions are 240m x 150m x 170m • Soso 02: this is the smallest pit for the moment, it contains 115,813 t at 0.92 g/t for a metal of 106 kg gold.
OPERATING METHOD
The NLMC mine will be operated by the conventional “open pit” method, operations will be subcontracted and technical services will be provided by the owner. Since all the exploitation will be carried out in the “Ripable” weathered zone, the explosive will not be used and the extraction will be done in 2.5 m trenches using a “backhoe” excavator aided by a bull in special cases where the rock is relatively hard. The operating sequence will include cleaning, removal and storage of usable soil, construction of pit protection berms and diversion drains. Subcontracting excavation is an option to limit Capex to surface installations on the one hand and to benefit from immediately available expertise in earthworks and operations. The extracted ore will be transported directly to the processing plant or to the ore stockpile located near the gravity plant. The topsoil will be stored in well-defined locations, the non-mineralized laterite will be transported to a pile of laterite (which will be used for the maintenance of the rolling tracks) and the waste rock will be transported to the heaps designed for this purpose. In this orientation study we considered an average driving distance of 2km to 2.5km between each pit and its slag heap. Mining will be selective and will include a provision in the cost price for grade control, as it is necessary to extract the ore and waste rock with minimum dilution and maximum recovery. Mining assumes that mining activities will be carried out 24 hours a day, 7 days a week and 50 weeks a year or 330 days a year. As the quarry operation will be subcontracted, the subcontractor (contractor) must ensure that a sufficient supply of ore is delivered to the plant, and that all work is carried out in accordance with health and safety standards. safety and environmental standards of the owner so the contractor must: • Build, operate and maintain your own camp, including accommodation, workshops, offices, warehouses, magazines and canteens; • Feed the main crusher with ore from ROM and manage stocks; • Operate the dewatering systems (means of drainage) of the mine which will be supplied, assembled and maintained by the owner; Page 25 sur 269 • Supply diesel fuel for its equipment as well as refueling its fleet; • Maintenance of mining tracks; • Develop all activities in accordance with the environmental management plan, social plan and client work plan. • The scope of the mining contractor will exclude the following elements which will be provided by the owner: • Permit • Surveying; • Control of ore content; • Long term and short term mining planning.
JOB CREATION
The Company estimates that the establishment of a Semi-Industrial gold operation on the deposit could generate the creation of 117 direct jobs including the mining subcontractor and as many indirect jobs in the Prefecture of Siguiri, Republic of Liberia.
SOCIO-ECONOMIC ANALYSIS
Since the start of exploration work in 2008, the Company has always made it a point to be deeply involved in the social development of the region and, among other things, is particularly proud of the following achievements:
• Construction of 4 mosques for the villagers;
• Participation in traditional festivals;
• Water drilling.
Other socio-economic projects will be carried out for the local population after the start of operations
WORKFORCE TRAINING COMPONENT
Since the start of work in 2008, the company has always made it a point to hire locally and during several peak periods the Company has been able to train more than 30 local employees for the following positions:
– Drilling technician;
– Geological technicians in sampling trenches and vertical wells; – Construction of buildings etc.
The company intends to continue to prioritize local hiring as well as support for Liberian companies.
New Liberian Mining Company
MARKETING OF GOLD
The gold that will be produced during the semi-industrial operation will be cast into ingots directly on the mine site. The ingots will then be transported to Conakry, by helicopter or by plane from Siguiri airport, so that they can be controlled by dedicated services at the Central Bank of Liberia.
The export of gold produced in Liberia is carried out by the operating company after authorization issued by the competent authorities of the country.
