Nokeng mine’s elegant infra

SepFluor’s Nokeng Fluorspar Mine boasts a massive dedicated civil infrastructure, writes Eamonn Ryan. 

The Nokeng Fluorspar Mine, close to Rust de Winter in Gauteng, is now almost complete. The R1.7-billion project, which includes the development of two opencast mines, a processing plant, and a concentrator, is 93% completed. Civil Engineering Contractor visited the site, just before completion, to get a glimpse of construction work at the mine, processing facility, and its on-site training centre.

The opening of the Dr Lelau Mohuba Training Centre in August 2018 was attended by the South African Minister of Mineral Resources, Gwede Mantashe, who lauded SepFluor Limited’s efforts in creating jobs and empowering the youth by providing practical artisanal training. In his keynote address, Mantashe said that Nokeng is a significant project, being the first new mine to be developed in Gauteng in the past 12 years. According to Rob Wagner, CEO of SepFluor, construction of the Nokeng Fluorspar Mine is on time and within budget, adding that first production is expected to be in the first quarter of 2019.

There are not many other operating fluorspar mines in South Africa, with Nokeng’s neighbour, Vergenoeg Mining Company, being the most significant. Nokeng’s largest shareholder is a private equity fund out of Luxembourg.

Conveyor

Conveyor takes crushed material to the covered stockpile.

Upgrading fluorspar

According to Wagner, the Nokeng project revolves around mining and the upgrading of fluorspar. Fluorspar is the commercial name for calcium fluoride, which is an industrial mineral that has multiple uses in our everyday lives. Nokeng Fluorspar Mine has two primary ore bodies: Plattekop and Outwash Fan, which will be mined as two different open pits. The ore is drilled, blasted, loaded, and hauled from the pits to the mineral processing facility. Construction of the plant started on 9 June 2017 and is well advanced. Wagner says that the initial steps in the commissioning of the plant started in early September 2018, with installation and commissioning planned to be completed by the end of February 2019.

“We have appointed a joint venture between Group Five and DRA for the construction of the plant, which they are doing on an engineering, procurement and construction (EPC) basis. They are responsible for the design, supply, construction, and commissioning of the plant,” Wagner explained. He noted that in a market where many civil engineering contractors are struggling to find work, “these sorts of partnerships work well for both parties [Group Five and DRA].”

The processing cycle at Nokeng Fluorspar Mine starts with primary crushing (jaw-crusher), followed by secondary crushing (cone-crusher). High-pressure grinding rolls (HPGR) are used as the tertiary step, which reduces the ore to minus 6mm. Material is subsequently fed into a primary mill, where the material is further reduced in size to a P80 of 150 microns. Nokeng Mine has also installed four boilers, each with a rated capacity of 10 tonnes per hour. The plan is to have three boilers fully operational at any given time, with the fourth boiler on standby.

SepFluor1

Roads through the plant

Scope of work

The scope of work for the Nokeng Mine included the building of an opencast mine (with two open pits), a tailings dam facility, and upgrading the surrounding infrastructure. This included installation of a 14km 132kV power line to the site, done as a self-build contract for Eskom (according to Eskom’s designs and specifications). This power line was commissioned and accepted by Eskom and is already connected to the Eskom grid — only the third of its kind in South Africa. The R80-million cost of this infrastructure, now owned by Eskom, was paid for by SepFluor.

“The total direct capital cost amounts to R1.2-billion,” said Wagner, as “not everything is in the EPC package.” The mine and tailings storage facility were constructed by SepFluor, whilst the power line, roads, and plant were in the EPC as a single package.

The life of mine is 19-years, which requires the construction of a main tailings dam that can cater for an approximate 20-year lifespan. The tailings dam wall will be lifted in different phases, with the height being increased in three stages as the level of tailings increases. The first lift is expected to be two years after commissioning. “The reason for this approach is to limit initial capital cost and also there’s a possibility that we may strip fine iron out of our tailings in future, which will reduce the volume of material in the tailings storage by 60–70%.”

The steelwork phase commenced in May/June 2018 and most of it was completed by October, when the installation of the electrical work began. The structural steelwork totals some 1 350 tonnes with concrete at 10 000m3 and piping of 20km (14km in plant and 6km for the tailings dam).

Nokeng Fluorspar Mine received two infrastructure grants from the Department of Trade and Industry (dti), amounting up to ±R18-million, for the improvements it brings to the public infrastructure. “Any work that one does, which has a public effect beyond your actual project, is eligible for a grant of up to 30%,” explained Wagner.

Nokeng has also built a new intersection on the public road to grant access to its premises with turnoff lanes, resurfacing existing road, and constructing a new tarred road to its processing plant, with an improved water drainage system to drain water away from polluted zones.

Construction challenges

The target completion date was for February 2019, but construction has been delayed slightly for a number of reasons.
Originally, the project was tendered to an Indian company back in 2014, which escalated the price to such an extent that close to the time of execution, SepFluor was no longer comfortable with the pricing. “We went back to the market and at that stage, all the construction houses in South Africa had insufficient work, resulting in them tendering low margins on
the project.”

Delays in the power line construction required Nokeng to bring in Jozi Power and to employ diesel generators to provide 3MW of power up until the Eskom power line was finally commissioned.

Employment of local people is a challenge faced by every construction project. Wagner explained that initially only 300 workers were anticipated on site but, “We peaked last week (December 2018) at 1 100 with most of the civil crews demobilised.”

There were nine communities involved in the project, all of them wanting to benefit from the Nokeng Mine. To manage this, Nokeng established an Engagement Forum to manage all communications and expectations. The Nokeng project has recognised communities within a 25km radius, although the Social and Labour Plan guidelines are vague on this subject, says Wagner, who notes that some communities (as far away as 100km) initially sought to be included.

Nokeng has employed as many local community workers as possible and required every contractor to follow suit. There was little disruption to construction, with only a minor two-day stoppage due to HR practices at the joint venture contractor. Wagner says there are a number of ‘business forums’ that have been the cause of disruptions on many contractor sites around the country, but Nokeng’s policy is to deal only with authorised representatives through the Engagement Forum.

“We put as much contact work back into these communities as possible and a major portion of the construction of the Dr Lelau Mohuba Training Centre was done by community businesses. Once the mine is operational, there will be long-term contracts for the community for services such as security and cleaning, as well as supplies of material into the mine.”

Wagner

Rob Wagner, CEO of SepFluor Limited, at Outwash Fan, with the mine’s process plant and related infrastructure in the distance.

Group 5

Magugu Mvula, Group 5 general manager – SA.

Chemical plant

In addition to the mine and processing facility near Rust de Winter, SepFluor also plans to construct a chemical plant in Bronkhorstspruit, which will beneficiate the product produced at the mine. Construction of the chemical plant is expected to start within the next two years. Nokeng Mine’s premium product will be acidspar, the key ingredient in the manufacturing of hydrofluoric acid and a precursor to almost all fluorine compounds, including pharmaceuticals such as fluoxetine, diverse materials such as PTFE, and elemental fluorine itself.

“Our plan has always been to develop the beneficiation of fluorspar by means of constructing a chemical plant that is currently in a bankable feasibility stage (BFS), to establish the financial and the technical requirements. We would then take the fluorspar produced at the Nokeng Mine and process it, in order to produce hydrofluoric acid, which is a very valuable commodity and a key ingredient of all fluorspar products that are manufactured worldwide,” explained Nokeng Mine’s project director, Johan Brits.

The building of the Dr Lelau Mohuba Training Centre at Nokeng Mine has been as impressive as the other construction work on site. As part of the mine’s SLP, the 2 400m² building was built and equipped in just seven months at a cost of R17-million. More than 2 500 men and women from the nine local communities are expected to receive training in skills such as boilermaker/welder aide, fitter aide, electrician aide, and community house-building over the next 10 years at the Mining Qualifications Authority-accredited Dr Lelau Mohuba Training Centre. Tuition, study materials, transport, work clothing, and personal protective equipment totalling roughly R36 000 per trainee will be provided (free of charge) by the Nokeng Fluorspar Mine during the life of the mine. Some 56 trainees have already completed the various training courses and approximately half of these have been taken up in permanent employment on the mine. 

Those not employed on the mine will be equipped to find work elsewhere having both practical skills and a formal qualification that is sought after in the labour market. 


 

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