Overview

Deposit type

• Banded iron formation

Summary:

Beeshoek is situated within a sequence of early Proterozoic sediments of the Transvaal Supergroup. It is located on the Maremane Anticline in the Griqualand West Sequence of the Transvaal Supergroup, as well as the Elim Group of the Keis Supergroup.

In general, two ore types are present: laminated hematite ore, forming part of the Manganore Iron Formation, and conglomerate ore, belonging to the Doornfontein Conglomerate Member at the base of the Gamagara Formation. The laminated ore types occur in the upper portion of the Manganore Iron Formation as enriched high-grade hematite bodies.

The boundaries of high-grade hematite orebodies cross-cut primary sedimentary bedding, indicating that secondary hematitisation of the iron formation took place. In all of these, some of the stratigraphic and sedimentological features of the original iron formation are preserved.

The conglomeratic ore found in the Doornfontein Conglomerate Member of the Gamagara Formation, is lenticular but not consistently developed along strike. It consists of stacked, upward fining conglomerate-gritstone-shale sedimentary cycles. The lowest conglomerates and gritstones tend to be rich in subrounded to rounded hematite ore pebbles and granules and form the largest part of the resource. The amount of iron ore pebbles decreases upwards in the sequence so that upper conglomerates normally consist of poorly sorted, angular to rounded chert and banded iron formation pebbles. Hematite is the predominant ore mineral, but limonite and specularite also occur.

Numerous deep iron ore extensions occur into the basins due to karst development. A prominent northsouth strike of the orebodies dipping to the west is notable. The southern Beeshoek orebodies were exposed to more erosion and hence are more localised and smaller. Outcrops are limited to the higher topography on the eastern side of the properties.

Down-dip to the west, the ore is thin and deep.

Mining Methods

• Truck & Shovel / Loader

Summary:

Mining operations are all open-pit, based on the conventional drill-and-blast, truck-and-shovel operations. Run-of-mine ore is crushed and stored as ‘on-’ or ‘off-grade’ on blending stockpiles.

The iron ore is exploited by means of conventional opencast mining techniques (drilling, blasting and load-haul). The drill-blast activities are contracted out, whereas load-haul is undertaken by a combination of owner and contractors’ fleets.

The vegetated soil overlying the mining area is stripped prior to mining and stockpiled on a dedicated dump to be used for rehabilitation purposes at a later stage. Then bench blocks of 10m height are drilled using drill rigs, which drill 165mm diameter blast holes. Drill patterns can be a staggered or square pattern, with burden and spacing varying from 4m x 5m in waste, to 3m x 3m in difficult ore. Blast holes are charged with emulsion explosives and different down-hole charge configurations are used depending on the different rock types to be blasted. This, together with the necessary blasting accessories, achieves optimal fragmentation.

The blasted rock is loaded with front-end loaders and excavators into rigid haul trucks and Articulated Dump Trucks (ADTs). Ore is hauled to the Primary Crusher and ore stockpiles. Based on the grade and destined metallurgical processes, numerous iron ore stockpiles exist on Beeshoek.

Another mining method utilised on Beeshoek Mine is the mining of detrital ore, where the deposits of ore are shallow enough to be scooped out of the ground for processing as opposed to employing more extensive opencast mining methods. There are a few of these detrital zones on the mine area which still need to be exploited.

Comminution

Crushers and Mills

Summary:

At Beeshoek, there are two lines consisting of a Primary and Secondary Crusher namely South Mine Crushing and North Mine Crushing. These primary plants consist of two stages of crushing, namely one primary crusher and one secondary crusher. At the primary crusher ore is crushed down to -200mm and at the secondary crusher it is further reduced to -80mm. In case of on-grade (ROM) ore feed, the secondary product is fed to the Washing and Screening Plant and contaminated ore or off-grade ore feeds, where beneficiation is needed, is fed to the Jig Plant. From the South Mine Crushing, ore is conveyed via an overland conveyor system to stockpiles at the plant area on North Mine. Following the primary and secondary crushing operations, the crushed ore is conveyed to the processing plant area, which is situated at North Mine.

Processing

• Wash plant
• Jig plant
• Crush & Screen plant
• Dewatering

Summary:

Run-of-mine ore is crushed and stored as “on-” or “off-grade” on blending stockpiles. Ore from the stockpiles is either sent to the wash-and-screen plants or, if “off-grade”, to the beneficiation plants. The washing and screening plants consist primarily of tertiary crushing, washing, screening, conveying and stacking equipment. The beneficiation plants consist of tertiary crushers; scrubbers; coarse and fine jigs; lumpy and fines product stockpiles; and a rapid load-out facility. No chemicals are being used in any of the processing plants.

On-grade and off-grade crushed ore is stockpiled separately with dedicated stackers and reclaimed to be fed separately to the dedicated ongrade and off-grade processing plants. On-grade ore requires only screening, while off-grade ore requires further beneficiation, to conform to the market requirements. The plans include the following:

-Washing and Screening Plant: The ROM feed is washed and sized into a lumpy fraction (+6mm –32mm), MS product (+6mm – 18mm) and a fines fraction (+0.5mm – 6mm). The primary screens oversize (+32mm) is conveyed to three tertiary crushers in closed circuit with the primary screens;

-Preparation Plant: The contaminated/ off-grade ore feed is washed and sized into a lumpy fraction (+8mm –25/32mm) and a fines fraction (+0.5mm – 8mm) prior to conveying to the Jig Plant. The screen oversize is conveyed to a tertiary crusher in closed circuit with the screens;

- Beneficiation is achieved by utilising Jig technology. Jigs separate the ore according to the specific density of the particles.

The washing and screening plants consist primarily of tertiary crushing, washing, screening, conveying and stacking equipment. The beneficiation plants consist of tertiary crushers; scrubbers; coarse and fine jigs; lumpy and fines product stockpiles; and a rapid load-out facility. No chemicals are being used in any of the treatment plants.

After the ore is mined and blended in the pits, it is loaded onto dump trucks and transported to the primary crushers. After crushing, the ore is stacked onto a longitudinal blending bed that serves as a buffer between the mining and the ore preparation plant at Beeshoek North.

The ore is then moved via conveyor to a scalping screen, where oversized rock is separated and transferred into a secondary crusher.

All crushed material is recombined and conveyed to the washing and screening section. Contaminated ore is directed to the jig facility for beneficiation.

The washing and screening plant is capable of handling 1,400 tons per hour at full capacity and is controlled within the processing equipment efficiency limitations to maintain the required chemical and physical criteria. After washing and screening, the final products – Lump, Fines and DR Lump – are stockpiled on final product stockpiles located at the mine’s railway siding.

The jig plant is capable of processing 650 tons lower grade contact ore per hour. After secondary crushing, the off-grade ore is placed on the feed stockpile at the jig plant. Ore is then pulled from the stockpile for tertiary crushing.

Subsequently, the material is stacked on to Lumpy and Fines jig stockpiles. The ore from these separate stockpiles is then fed into the jig plant, where pulsating water flows into the bed to separate the less dense fraction waste from the denser fraction middling and high quality ore. The waste is dewatered on screens and conveyed to a waste stockpile. The middling and high quality ore is passed over its own dewatering screens before being conveyed to separate conical stockpiles. Feeders beneath these stockpiles combine the products into the desired ratio to produce a beneficiated product ready for blending into the final product.

The final products is then stockpiled onto the same final product stockpiles as the washing plant product.

Water Supply

Summary:

Beeshoek is located in Water Management Area (WMA) 10: Lower Vaal.

Mainly groundwater from boreholes, as well as water from the Vaal-Gamagara/ Sedibeng Water Supply Scheme, are the main sources of potable water to the Beeshoek mining complex for usage at the Village, the Plant, and workshop and office areas.

Potable water for use by the mine is obtained from the dewatering boreholes approved in terms of the WUL of the opencast pit area within the South Mine. Water is also obtained from the Vaal Gamagara Water Supply Scheme. The water is collected in two concrete reservoirs at the entrance to the South Mine where the water is disinfected for further distribution on the mine site.

To provide greater flexibility as areas are mined out, Beeshoek Mine has applied for an amendment to its WUL to allow for additional dams and new boreholes. These measures would help reduce reliance on water from Kolomela Mine via the Vaal Central Water Board. The outcome of this application is pending. The new stormwater dam, commissioned in F2020, enabled the mine to better separate clean and dirty water during flooding events in F2021. In F2022, additional investments were made in pumping capacity and road designs were revised to improve water drainage. Previously, the mine has also invested in mobile pumps and software to optimise dust suppression using water trucks.

Production

Operational metrics

Personnel

Job Title	Name	Phone	Email	Profile	Ref. Date
Senior General Manager	Maryke Burger	+27 (0) 53 311 6666	Maryke.Burger@assmang.co.za		Nov 5, 2023
Technical Services Manager	Dorianne Odendaal	+27 (0) 53 311 6666	dorianne.odendaal@assmang.co.za		Nov 5, 2023