AngloGold Ashanti PLC

Banded iron formation (BIF): A chemical sediment, typically thin-bedded or laminated with greater than 15 percent iron of sedimentary origin.

By-products: Any potentially economic or saleable products that emanate from the core process of producing gold or copper, including silver, molybdenum and sulphuric acid.

Carbon-in-leach (CIL): Gold is leached from a slurry of ore where cyanide and carbon granules are added to the same agitated tanks. The gold loaded carbon granules are separated from the slurry and treated in an elution circuit to remove the gold.

Carbon-in-pulp (CIP): Gold is leached conventionally from a slurry of ore with cyanide in agitated tanks. The leached slurry then passes into the CIP circuit where activated carbon granules are mixed with the slurry and gold is adsorbed on to the activated carbon. The gold-loaded carbon is separated from the slurry and treated in an elution circuit to remove the gold.

Comminution: Comminution is the crushing and grinding of ore to make gold available for physical or chemical separation (see also “Milling”).

Contained gold or Contained copper: The total gold or copper content (tonnes multiplied by grade) of the material being described.

Cut-off grade: Cut-off grade is the grade (i.e., the concentration of metal or mineral in rock) that determines the destination of the material during mining. For purposes of establishing “prospects of economic extraction,” the cut-off grade is the grade that distinguishes material deemed to have no economic value (it will not be mined in underground mining or if mined in surface mining, its destination will be the waste dump) from material deemed to have economic value (its ultimate destination during mining will be a processing facility). Other terms used in similar fashion as cut-off grade include net smelter return, pay limit, and break-even stripping ratio.

Depletion: The decrease in the quantity of ore in a deposit or property resulting from extraction or production.

Development: The process of accessing an orebody through shafts and/or tunneling in underground mining operations.

Development stage property: A development stage property is a property that has Mineral Reserve disclosed, but no material extraction.

Diamond drilling (DD): A form of core drilling which uses a rotary drill with a diamond drill bit attached in order to create precisely measured drill holes.

Diorite: An igneous rock formed by the solidification of molten material (magma).

Doré: Impure alloy of gold and silver produced at a mine to be refined to a higher purity.

Economically viable: Economically viable, when used in the context of Mineral Reserve determination, means that the Qualified Person has determined, using a discounted cash flow analysis, or has otherwise analytically determined, that extraction of the Mineral Reserve is economically viable under reasonable investment and market assumptions.

Electrowinning: A process of recovering gold from solution by means of electrolytic chemical reaction into a form that can be smelted easily into gold bars.

Elution: Recovery of the gold from the activated carbon into solution before zinc precipitation or electrowinning.

Exploration results: Exploration results are data and information generated by mineral exploration programmes (i.e., programmes consisting of sampling, drilling, trenching, analytical testing, assaying, and other similar activities undertaken to locate, investigate, define or delineate a mineral prospect or mineral deposit) that are not part of a disclosure of Mineral Resource or Mineral Reserve. A registrant must not use exploration results alone to derive estimates of tonnage, grade, and production rates, or in an assessment of economic viability.

Exploration stage property: An exploration stage property is a property that has no Mineral Reserve disclosed.

Exploration target: An exploration target is a statement or estimate of the exploration potential of a mineral deposit in a defined geological setting where the statement or estimate, quoted as a range of tonnage and a range of grade (or quality), relates to mineralisation for which there has been insufficient exploration to estimate a Mineral Resource.

Feasibility study: A feasibility study is a comprehensive technical and economic study of the selected development option for a mineral project, which includes detailed assessments of all applicable modifying factors, as defined by this section, together with any other relevant operational factors, and detailed financial analyses that are necessary to demonstrate, at the time of reporting, that extraction is economically viable. The results of the study may serve as the basis for a final decision by a proponent or financial institution to proceed with, or finance, the development of the project. A feasibility study is more comprehensive, and with a higher degree of accuracy, than a pre-feasibility study. It must contain mining, infrastructure, and process designs completed with sufficient rigour to serve as the basis for an investment decision or to support project financing. The confidence level in the results of a feasibility study is higher than the confidence level in the results of a pre-feasibility study. Terms such as full, final, comprehensive, bankable, or definitive feasibility study are equivalent to a feasibility study.

Flotation: Concentration of gold and gold-hosting minerals into a small mass by various techniques (e.g. collectors, frothers, agitation, air-flow) that collectively enhance the buoyancy of the target minerals, relative to unwanted gangue, for recovery into an over-flowing froth phase.

Gold produced or Gold production: Refined gold in a saleable form derived from the mining process.

Grade: The quantity of ore contained within a unit weight of mineralised material generally expressed in grams per metric tonne (g/t) or ounce per short tonne for gold bearing material or Percentage copper (%Cu) for copper bearing material.

Greenschist: A schistose metamorphic rock whose green colour is due to the presence of chlorite, epidote or actinolite.

Indicated Mineral Resource: An Indicated Mineral Resource is that part of a Mineral Resource for which quantity and grade or quality are estimated on the basis of adequate geological evidence and sampling. The level of geological certainty associated with an Indicated Mineral Resource is sufficient to allow a Qualified Person to apply modifying factors in sufficient detail to support mine planning and evaluation of the economic viability of the deposit. Because an Indicated Mineral Resource has a lower level of confidence than the level of confidence of a Measured Mineral Resource, an Indicated Mineral Resource may only be converted to a Probable Mineral Reserve.

Inferred Mineral Resource: An Inferred Mineral Resource is that part of a Mineral Resource for which quantity and grade or quality are estimated on the basis of limited geological evidence and sampling. The level of geological uncertainty associated with an Inferred Mineral Resource is too high to apply relevant technical and economic factors likely to influence the prospects of economic extraction in a manner useful for evaluation of economic viability. Because an Inferred Mineral Resource has the lowest level of geological confidence of all Mineral Resource, which prevents the application of the modifying factors in a manner useful for evaluation of economic viability, an Inferred Mineral Resource may not be considered when assessing the economic viability of a mining project, and may not be converted to a Mineral Reserve.

Initial assessment (also known as concept study, scoping study, conceptual study and preliminary economic assessment): An initial assessment is a preliminary technical and economic study of the economic potential of all or parts of mineralisation to support the disclosure of Mineral Resource. The initial assessment must be prepared by a Qualified Person and must include appropriate assessments of reasonably assumed technical and economic factors, together with any other relevant operational factors, that are necessary to demonstrate at the time of reporting that there are reasonable prospects for economic extraction. An initial assessment is required for disclosure of Mineral Resource but cannot be used as the basis for disclosure of Mineral Reserve.

Leaching: Dissolution of gold from crushed or milled material, including reclaimed slime, prior to adsorption on to activated carbon or direct zinc precipitation.

Life-of-mine (LOM): Number of years for which an operation is planning to mine and treat ore, and is taken from the current mine plan.

Localised uniform conditioning (LUC): A technique developed to spatially locate selective mining unit grades that have been derived using uniformed conditioning.

Long hole open stoping (LHOS): A form of sub-level open stoping which involves excavating ore in a series of horizontal or sub-horizontal levels, known as stopes. This method is used in both hard rock and soft rock mining operations and is ideal for mining steeply dipping ore bodies, where it is more challenging to drill parallel drifts and cross cuts.

Longitudinal retreat stoping (LRS): A mining method used for continuous extraction along the length of narrow veins and can be mechanised to some extent.

Measured Mineral Resource: A Measured Mineral Resource is that part of a Mineral Resource for which quantity and grade or quality are estimated on the basis of conclusive geological evidence and sampling. The level of geological certainty associated with a Measured Mineral Resource is sufficient to allow a Qualified Person to apply modifying factors, as defined in this section, in sufficient detail to support detailed mine planning and final evaluation of the economic viability of the deposit. Because a Measured Mineral Resource has a higher level of confidence than the level of confidence of either an Indicated Mineral Resource or an Inferred Mineral Resource, a Measured Mineral Resource may be converted to a Proven Mineral Reserve or to a Probable Mineral Reserve.

Metallurgical plant / gold plant / plant: A processing plant constructed to treat ore and extract gold or copper in the case of Quebradona (and, in some cases, valuable by-products).

Metallurgical recovery factor (MetRF): A measure of the efficiency in extracting gold, silver or copper from the ore.

Milling: A process of reducing broken ore to a size at which concentrating or leaching can be undertaken (see also “Comminution”).

Mine call factor (MCF): The ratio, expressed as a percentage, of the total quantity of recovered and unrecovered mineral product after processing with the amount estimated in the ore based on sampling. The ratio of contained gold delivered to the metallurgical plant divided by the estimated contained gold of ore mined based on sampling.

Mineable shape optimiser (MSO): A widely recognised industry-standard software tool used to generate the optimal size, shape and location of stopes for underground mine design.

Mineralisation: The process or processes by which a mineral or minerals are introduced into rock, resulting in a potentially valuable deposit.

Mineral deposit: A mineral deposit is a concentration (or occurrence) of material of possible economic interest in or on the earth’s crust.

Mineral Reserve: A Mineral Reserve is an estimate of tonnage and grade or quality of Indicated and Measured Mineral Resource that, in the opinion of the Qualified Person, can be the basis of an economically viable project. More specifically, it is the economically mineable part of a Measured or Indicated Mineral Resource, which includes diluting materials and allowances for losses that may occur when the material is mined or extracted. Mineral Reserve is subdivided in order of increasing confidence into Probable Mineral Reserve and Proven Mineral Reserve. Mineral Reserve is aggregated from the Proven and Probable Mineral Reserve categories. A Measured Mineral Resource may be converted to either a Proven Mineral Reserve or a Probable Mineral Reserve depending on uncertainties associated with modifying factors that are taken into account in the conversion from Mineral Resource to Mineral Reserve. The Mineral Reserve tonnages and grades are estimated and reported as delivered to plant (i.e., the point where material is delivered to the processing facility).

Mineral Resource: A Mineral Resource is a concentration or occurrence of material of economic interest in or on the Earth's crust in such form, grade or quality, and quantity that there are reasonable prospects for economic extraction. A Mineral Resource is a reasonable estimate of mineralisation, taking into account relevant factors such as cut-off grade, likely mining dimensions, location or continuity, that, with the assumed and justifiable technical and economic conditions, is likely to, in whole or in part, become economically extractable. It is not merely an inventory of all mineralisation drilled or sampled. Mineral Resource is subdivided and must be so reported, in order of increasing confidence in respect of geoscientific evidence, into Inferred, Indicated or Measured categories. The Mineral Resource tonnages and grades are reported in situ and stockpiled material is reported as broken material.

Mining recovery factor (MRF): This factor reflects a mining efficiency factor relating to the recovery of material during the mining process and is the variance between the tonnes called for in the mining design and what the plant receives. It is expressed in both a grade and tonnage number.

Modifying Factors: Modifying factors are the factors that a Qualified Person must apply to Indicated and Measured Mineral Resource and then evaluate in order to establish the economic viability of Mineral Reserve. A Qualified Person must apply and evaluate modifying factors to convert Measured and Indicated Mineral Resource to Proven and Probable Mineral Reserve. These factors include, but are not restricted to: mining; processing; metallurgical; infrastructure; economic; marketing; legal; environmental compliance; plans, negotiations, or agreements with local individuals or groups; and governmental factors. The number, type and specific characteristics of the modifying factors applied will necessarily be a function of and depend upon the mineral, mine, property, or project.

Open pit mining: An excavation made at the surface of the ground for the purpose of extracting minerals, inorganic and organic, from their natural deposits, which excavation is open to the surface.

Ounce (oz) (troy): Used in imperial statistics. A kilogram is equal to 32.1507 ounces. A troy ounce is equal to 31.1035 grams.

Pay limit: The grade of a unit of ore at which the revenue from the recovered mineral content of the ore is equal to the sum of total cash costs, closure costs, Mineral Reserve development and stay-in-business capital. This grade is expressed as an in-situ value in grams per tonne or ounces per short ton (before dilution and mineral losses).

Precipitate: The solid product formed when a change in solution chemical conditions results in conversion of some pre-dissolved ions into solid state.

Preliminary feasibility study (pre-feasibility study): is a comprehensive study of a range of options for the technical and economic viability of a mineral project that has advanced to a stage where a Qualified Person has determined (in the case of underground mining) a preferred mining method, or (in the case of surface mining) a pit configuration, and in all cases has determined an effective method of mineral processing and an effective plan to sell the product. A pre-feasibility study includes a financial analysis based on reasonable assumptions, based on appropriate testing, about the modifying factors and the evaluation of any other relevant factors that are sufficient for a Qualified Person to determine if all or part of the Indicated and Measured Mineral Resource may be converted to Mineral Reserve at the time of reporting. The financial analysis must have the level of detail necessary to demonstrate, at the time of reporting, that extraction is economically viable. A pre-feasibility study is less comprehensive and results in a lower confidence level than a feasibility study. A pre-feasibility study is more comprehensive and results in a higher confidence level than an initial assessment.

Probable Mineral Reserve: A Probable Mineral Reserve is the economically mineable part of an Indicated and, in some cases, a Measured Mineral Resource.

Production stage property: A production stage property is a property with material extraction of Mineral Reserve.

Productivity: An expression of labour productivity based on the ratio of ounces of gold produced per month to the total number of employees in mining operations.

Proven Mineral Reserve: A Proven Mineral Reserve is the economically mineable part of a Measured Mineral Resource and can only result from conversion of a Measured Mineral Resource.

Qualified Person: A Qualified Person, in respect of the Company's material properties, is an individual who is (1) a mineral industry professional with at least five years of relevant experience in the type of mineralisation and type of deposit under consideration and in the specific type of activity that person is undertaking on behalf of the registrant; and (2) an eligible member or licensee in good standing of a recognised professional organisation at the time the technical report is prepared. Regulation S-K 1300 details further recognised professional organisations and also relevant experience.

Quartz: A hard mineral consisting of silica dioxide found widely in all rocks.

Recovered grade: The recovered mineral content per unit of ore treated.

Reef: A gold-bearing horizon, sometimes a conglomerate band, that may contain economic levels of gold. Reef can also be any significant or thick gold bearing quartz vein.

Refining: The final purification process of a metal or mineral.

Regulation S-K 1300: Subpart 1300 of Regulation S-K (17 CFR § 229.1300) which contains the SEC’s mining property disclosure requirements for mining registrants.

Rehabilitation: The process of reclaiming land disturbed by mining to allow an appropriate post-mining use. Rehabilitation standards are defined by country-specific laws, including but not limited to the US Bureau of Land Management, the US Forest Service, and the relevant Australian mining authorities, and address among other issues, ground and surface water, topsoil, final slope gradient, waste handling and re-vegetation issues.

Resource modification factor (RMF): This factor is applied when there is an historic reconciliation discrepancy in the Mineral Resource model (e.g. between the Mineral Resource model tonnage and the grade control model tonnage). It is expressed in both a grade and tonnage number.

Reverse circulation (RC) drilling: A form of percussion drilling that uses compressed air to flush material cuttings out of the drill hole.

Run-of-mine (ROM): The unprocessed mined material which consists of the soil and rock of overburden, minerals, middlings, contamination and impurities.

Scats: Within the metallurgical plants, scats is a term used to describe ejected ore or other uncrushable / grinding media arising from the milling process. This, typically oversize material (ore), is ejected from the mill and stockpiled or re-crushed via a scats retreatment circuit. Retreatment of scats is aimed at fracturing the material such that it can be returned to the mills and processed as with the other ores to recover the gold locked up within this oversize material.

Seismic event: A sudden inelastic deformation within a given volume of rock that radiates detectable seismic energy.

Selective mining unit (SMU): This concept comes out of geostatistical estimation and relates to the smallest unit that can be mined selectively. This will vary with the style of the mineralisation, the mining method and equipment size. The concept is to select the smallest regular cell size that can be practically mined by appropriately sized mining equipment.

Shaft: A vertical or subvertical excavation used for accessing an underground mine; for transporting personnel, equipment and supplies; for hoisting ore and waste; for ventilation and utilities; and/or as an auxiliary exit.

Smelting: A pyro-metallurgical operation in which gold precipitate from electro-winning or zinc precipitation is further separated from impurities.

Stoping: The process of excavating ore underground.

Stripping ratio: The ratio of waste tonnes to ore tonnes mined calculated as total tonnes mined less ore tonnes mined divided by ore tonnes mined.

Sub-level open stoping (SLOS): This method is a variation of open stoping that involves dividing the ore body into horizontal slices or sub-levels. Each sub-level is mined progressively, starting from the bottom, with drilled holes for blasting and ore removal. The method allows for selective ore mining and can be adapted to varying vein widths.

Tailings: Finely ground rock of low residual value from which valuable minerals have been extracted.

Tailings storage facility: Facility designed to store discarded tailings.

Tonnage: Quantity of material measured in tonnes.

Tonne: Used in metric statistics. Equal to 1,000 kilograms.

Tonnes treated: This is the volume of gold-bearing ore processed and treated at our on-site gold plants to extract the gold and silver. Tonnes treated are often used to calculate efficiency or intensity of use data such as GHG emissions and water used per tonne treated.

Total recordable injury frequency rate (TRIFR): The total number of recordable injuries and fatalities that occurs per million hours worked.

Traverse open stoping (TOS): One of the most used underground mining methods is open stope mining which involves extracting a large body of ore through drilling and blasting. This mining method allows for complex stope sequencing, and is considered more efficient for mining wide, steep orebodies.

Underground mining: The extraction of rocks, minerals and industrial materials, other than coal, oil and gas, from the earth by developing entries or shafts from the surface to the seam or deposit before recovering the product by underground extraction methods.

Underhand drift and fill (UHDF): A mining method which follows the local variations to the orebody and is considered to provide greater control on excavation and stability, with reduced dilution and increased mining recovery outcomes.

Uniform conditioning (UC): The uniform conditioning method estimates a tonnage and grade of mineralisation that can be recovered using the selective mining unit at the chosen cut-off value.

Waste: Material that contains insufficient mineralisation for consideration for future treatment and, as such, is discarded.

Yield: The amount of valuable mineral or metal recovered from each unit mass of ore expressed as grams per metric tonne.

Zinc precipitation: Zinc precipitation is the chemical reaction using zinc dust that converts gold in solution to a solid form for smelting into unrefined gold bars.