Property Geology and Mineralization
The AGM deposits are hosted along the NE-SW Asankrangwa structural shear corridor, which is defined by NE-SW trending lineaments and magnetic lows and is about 7 km wide and over 50 km long.

Nkran
Nkran occurs on a 20° trending jog on the Nkran Shear Corridor. The Nkran Shear is characterized by sheared siltstones (phyllites) dominant on the western side of the shear and sandstone dominant on the east. The central part of the Nkran deposit consists of a series of wacke and sandstone-dominated stratigraphy that has been intruded by several felsic porphyry intrusions (see Davis, 2016). Consistent mappable lithologies are the western sandstone, the central sandstone, the eastern sandstone, the felsic granitic porphyry intrusive unit, and the skinny breccia unit which is located within the eastern sandstones and runs along the strike of the deposit.

Esaase
Broadly speaking, the Esaase deposit area can be referred to as a ‘system of gold-bearing quartz veins hosted by tightly folded Birimian-age sedimentary rocks arranged along an NNE-SSW trending strike’. Since the maiden resource release in October 2007, various simplified geological models have been used to constrain the resource estimation.

Akwasiso
The Akwasiso deposit lies some 4 km NE of the main Nkran deposit and geologically bears many similarities to Nkran. A granite intrusion surrounds a 080° dipping cross structure and mineralization hosted in bounding 035°N sub-vertical shear structures transgressing a sandstone/siltstone sequence.

Abore
The Abore deposit is located on the Abore-Esaase shear corridor which also hosts the Esaase deposit. The main rock types observed within the Abore pit consist of carbonaceous shale, siltstone (phyllite), thinly bedded wacke, and thickly bedded sandstone. The sedimentary sequence has been intruded by a granitic (tonalitic) intrusion.

Asuadai
The Asuadai deposit is located on the regional NE trending Nkran shear zone, approximately 10 km long strike from Nkran. The prospect features a massive intermediate (tonalite) granitoid hosting a quartz stockwork system.

Adubiaso
The Adubiaso geology comprises a sub-vertical stratigraphy of interbedded greywacke and phyllite, with three sub-vertical granite (porphyry) dykes obliquely cross-cutting the stratigraphy. A steep dipping (65° E) quartz vein system cuts across Birimian metasedimentary rocks, which dip steeply at 75° to the west. The vein system appears to be related to a NE fracture system (distinct from the Nkran structure) along the contact zone between dominantly phyllitic units on the east and coarser greywackes on the west, which host most of the gold-bearing veins. The central part of the vein system is 15 m to 20 m wide, but it tapers to about 10 m at both ends; the vein system has a strike length of about 700 m although the main area of economic significance is the central 300 m of the zone.

Miradani North
The Miradani North deposit was mined between 1996 and 2016 by previous operators. The pit is 250 m long by about 120 m wide with a depth of about 60 m. Most of the oxide ore is depleted but the fresh rock remains untouched.

Dynamite Hill
The Dynamite Hill deposit is located on the Nkran shear trend about 7 km north of the Nkran pit and 4 km north of the Akwasiso pit where it offsets a regional north-south mafic dyke and a localized east-west crosscutting structure. The area is underlain by fine to medium-grained greywackes (intermittent strong alterations) intercalated with argillites (phyllites), and intrusions of altered felsic rock (feldspar quartz porphyry/granitoid), quartz veins, and stockworks. The initial depth of oxidation was between 20 to 50 m below the surface on rugged terrain but a portion of the oxidized rock has been mined out. The deposit was mined in 2018 from an RL of about 330 m to 180 m.

DEPOSIT TYPES
Two broad styles of gold deposits are present in southwest Ghana:
• Structurally controlled lode or orogenic gold deposits
• Paleoplacer disseminated gold deposits in Tarkwaian conglomerates.

The primary controls on mineralization in the Asankrangwa Belt are structural in origin. Certain sandstone units within the Birimian metasedimentary package provided favourable rheological conditions that optimized gold deposition often close to major lithological contacts with either Birimian metavolcanic rocks or Tarkwaian metasedimentary rocks (Griffis et al, 2002). The deposit type targeted by the AGM is this structurally controlled mesothermal quartz vein style mineralization (orogenic gold type deposits). This is the most important type of gold occurrence in West Africa and is commonly referred to as the Ashanti-type. Milesi et al. (1992) recognized that mesothermal quartz vein style deposits are largely confined to tectonic corridors that are often over 50 km long and up to several kilometres wide and usually display complex, multi-phase structural features, which control the mineralization.

There are at least two separate gold mineralizing events that are linked to the structural evolution of the area. Mineralization is linked to:
• Early isoclinal folding, shearing and/or duplexing of stratigraphy controlling the location of deformation zones and fluid flow
• A late approximate east-west compressional event that generated shallow dipping to flat orientated conjugate vein sets that crosscut the earlier rock fabric and gold mineralization.

This brittle style deformation postdates the emplacement of granitic intrusive units into the core of the existing deformed and sheared sedimentary rocks. Orogenic gold deposits formed between 2.2 and 2.0 Ga, intrusionrelated (and skarn) between 2.2 and 2.1 Ga, and paleoplacer types between 2.06 and 1.8 Ga.

Gold mineralization is associated with major NE striking, 5 m to 40 m wide graphite-chlorite-sericite bearing fault zones. In particular, gold mineralization is developed where the NE fault zones intersect major ENE striking fault zones, and especially where they are recognized to have influenced granite emplacement, alteration and gold geochemical trends.

Left stepping flexures (10 km to 30 km scale) in the NE striking fault zones (which produce more northerly striking fault sections), are important for the localization of gold mineralization. Other local complexities in stratigraphy and fault geometry, associated with major NE striking faults, are also important for example, folds in stratigraphy that may produce saddle reef style mineralization, or fault duplexes.

The most common host rock is usually fine-grained metasedimentary units, often in close proximity to graphitic, siliceous, or manganiferous chemical sediments. However, in some areas, mafic volcanic rocks and belt intrusions are also known to host significant gold occurrences. Refractory type deposits feature early-stage disseminated sulphides in which pyrite and arsenopyrite host important amounts of gold overprinted by extensive late stage quartz veining in which visible gold is fairly common and accessory polymetallic sulphides are frequently observed. This type includes important lode/vein deposits in Ghana such as at the Obotan and Esaase area. A second non-refractory style of gold mineralization occurs in which gold is not hosted within sulphide minerals either in early, or late stage mineralization. These deposit types have lower sulphide content in general and often lack the needle-like arsenopyrite that is common in the refractory type deposits.

The Asanko Gold deposits demonstrate a late (second) phase of gold mineralization hosted in granitoids (Nkran basin type granite), emplaced in regional shear corridors. The deposits are situated within the Birimian metasedimentary units, but the granitoid intrusions and mineralization both occur at contacts between greywacke and carbonaceous phyllite units.

Mining by conventional open pit methods of drill and blast followed by load and haul will be employed. Drilling and blasting will be performed on 6 m benches. Loading of the blasted material will be performed on two 3 m flitches. Mining is currently undertaken by two separate mining contractors under the direction of Asanko Gold management.

The primary mining fleet of trucks and excavators is supported by standard open-pit drilling and auxiliary equipment. GC drilling ahead of mining is standard practice. Mining operations occur around the clock on two 12-hour shifts. A pre-split wall control method is being implemented along all the pit walls in the fresh zones to ensure the stability of the pit walls.

Blending strategy
The mine plan was developed around a 5.4 Mtpa processing throughput, where between 20% and 50% of the feed is oxide. A blending program is followed throughout the LOM that consider grade-bins, oretypes and Bond-work-index (BWI).

Mining operations
Grade control
Grade control (GC) drilling and sampling will be required to determine whether material in a given area is above, or below the cut-off grade. The ore is not anticipated to be visually controlled in the active mining face. GC definition drilling and sampling will be required to delineate the ore zone prior to the blast planning of the ore blocks.

Site preparation
The entire mining area will be cleared of buildings, installations and vegetation to a depth of 0.3 m. All building rubble, trees, bushes and other vegetable matter shall be stockpiled separately at designated locations. Vegetation suitable for use as firewood shall be stockpiled separately to all other cleared vegetation. The actual depth recovered will vary depending on location and based on recommendations from the Environmental department. All areas, where topsoil stripping occurs, will be surveyed before and after topsoil removal. The topsoil will be pushed into piles by a dozer or grader before a loader or excavator is used to load it into trucks. Trucks will then haul the soil to stockpiles for later use on rehabilitation, or directly to active rehabilitation areas. Prior to topsoil deposition, the stockpile areas will be cleared and surveyed.

Drill and blast Ore and waste will be broken using conventional drilling and blasting techniques. Experience gained to date during operation of the mine has shown that it is possible to free dig some of the material using either backhoe excavators or by ripping with a CAT D9 dozer, (or equivalent).

Load and haul
The mining fleet for the major pits (Nkran and Esaase) will include CAT 6030, 300 t hydraulic backhoe excavators with a 17 m3 bucket capacity, or equivalent, and face shovels with a 16.5 m3 bucket and CAT 6015, 140 t hydraulic backhoe excavator with a 6 m3 bucket capacity or equivalent. The primary hauling fleet will be CAT 777D dump trucks with a 94 t capacity. The mining fleet for the Satellite Pits will typical include CAT 390, 90 t hydraulic excavators with a 6 m3 bucket capacity, or equivalent, and CAT 374, 70 t hydraulic excavators with a 4.5 m3 bucket capacity or equivalent. Excavation will be executed from the mining dig plan as provided by the mine planning team to the operations team, with ore being hauled from the pits to the respective ore ROM pad, or directly to the crusher. Ore will be separated in different grade bins and material types outside the pit area, from where it will be transported by road haul trucks over land to the Nkran ROM pad for feeding into the Obotan plant.

Ore blending operations
Ore stockpiles will be used to manage the feed requirements. The configuration and capacity of the ore handling system will have the capability for direct blended ore feed, or alternatively switch-over between Oxide/ Transitional and Fresh material as and when required. Refer to the Section 17 (processing) on the importance of ore blending for process recovery, preg-robbing, BWI and process throughput. The proposed stockpile management will consist of buffer stockpiles which include Oxide, Transitional and Fresh material, located close to the primary crusher. It is estimated that 25% of the plant feed tonnage will be directly tip into the crusher and the remaining 75% will require re-handle using a CAT 992 front end loader (or equivalent) and CAT 777D haul truck. This is managed as per discussion in Section 16.1.2. Although direct tipping will be the preferred option, to minimise double-handling cost, this will be superseded by blending requirements. A longer-term strategic stockpile located approximately 750 m from the ROM pad will be maintained to balance the mining schedule with the plant feed schedule.

The AGM continues to apply a differential stockpiling and feed arrangement process for Esaase to prioritize higher margin material on the haul road.  As a consequence, mined grades may be higher than plant feed grades during a reporting period.

Crushing
Esaase sourced ore
ROM Esaase ore P100 of 800 mm is loaded onto haul trucks which transport the ore approximately 28 km to Obotan, where it is crushed in the Obotan crushing plant and thereafter joins the Obotan crushed ore ahead of feeding to the milling circuit.

Obotan Source
The primary crushing circuit consists of a single tip with a dedicated ROM bin and a single jaw crusher in open circuit. Primary crusher product reports to the crushed ore stockpile (COS). The ROM (F100 800 mm, F80 500 mm) is loaded into a 100 t ROM bin by means of a front-end loader (FEL), or by direct tipping by haul trucks.

The ROM is drawn from the ROM bin at a controlled rate by a single, variable speed apron feeder, and fed directly to the jaw crusher. The speed of the apron feeder is controlled to maintain crusher throughput. Fine material spillage from the apron feeder reports to the primary crushing conveyor, where it is combined with the primary crusher product (P100 300 mm, P80 125 mm). The primary crushing conveyor is fitted with a belt magnet to remove any tramp iron material. The primary crushing conveyor discharges the crushed material onto the COS.

Milling
The milling circuit is configured as a SAG milling, ball milling, crushing circuit (SABC circuit) comprising a primary SAG mill, a secondary Ball mill and a pebble crushing circuit. Ore is withdrawn from the 1,550 t COS by apron feeders feeding onto the SAG mill feed conveyor. A weightometer indicates the instantaneous and totalised crushed ore mill feed tonnage and is used to control the SAG mill feed rate via the apron feeders as well as the supplementation rate of the feed with the Esaase oxide material. The SAG mill feed conveyor discharges directly into the SAG mill feed hopper. The SAG mill discharge is screened via a 12 mm x 30 mm aperture trommel screen before gravitating to the mill discharge tank. Screen oversize is conveyed to a single pebble crusher, where it is crushed to below 12 mm prior to recycling back to mill feed conveyor. The pebble crusher feed conveyor is fitted with a weightometer for control purposes. A SAG mill pebble bunker is installed, in which any pebble overflow is stored for further handling.

The SAG mill operates in open circuit, discharging directly into the ball mill discharge sump, and in closed circuit with the pebble crusher. The ball mill discharges into a sump from where the slurry is pumped to the cyclone classification circuit. A portion of the cyclone underflow (84% target) is diverted to the three gravity concentration units, each with its own scalping screen, which removes the oversize fraction and diverts this back to the ball mill discharge sump. The remaining cyclone underflow portion reports back to the ball mill discharge sump for further grinding. Gravity recovered gold concentrate reports to an intensive leaching reactor circuit (ILR) while the gravity tailings reports back to the ball mill discharge sump.

Cyclone overflow gravitates to the pre-leach thickening circuit, comprising a single high rate thickener, where it is thickened to approximately 50% solids ahead of leaching and gold adsorption in the CIL circuit. Supernatant solution overflowing the thickener is recycled back to the process plant.

Quicklime is stored in a 100 t silo and is metered onto the mill feed conveyor using a variable speed screw feeder. Quicklime is delivered to site by tanker and pneumatically transferred to the lime silo using an off-loading blower.

A ball loading system is used for loading of grinding media into the SAG mill (via the mill feed conveyor).

Dust control is by way of a water dust suppression system at the stockpile area.

A mobile crushing array is used to assist with crushing of the ROM material, to optimize fragmentation and maintain throughput in the crushing circuit. Dust suppression, for dust control, is used at the crushing circuit.

The existing Asanko Gold Mine process plant located at Obotan is capable of processing approximately 5.8 Mtpa of total mill feed. Esaase material is being processed at present with supplementary feed from Akwasiso.

Gravity gold recovery
Gravity concentrate originating from the three milling gravity recovery concentrators is treated in two ILRs. These reactors contain elevated levels of cyanide, caustic soda and oxygen to enable maximum leaching of the precious metals in the concentrate. Leach residence time is approximately 18 hours. At the end of the leach cycle the pregnant solution is treated for Au recovery in two dedicated electrowinning cells to facilitate separate metallurgical accounting. ILR residue is pumped to the mill discharge sump. Overall gravity recovery is approximately 50%.

Pre-leach thickening
The secondary ball mill classification cyclone overflow stream gravitates to a horizontal vibrating trash removal screen, to remove a ........