Tag Archives: Lesotho

Integrated Pump Rental up for southern Africa pit dewatering challenge

As open-pit mines continue to get deeper with the maturing of operations, pit dewatering is becoming more vital, with ground water not only posing an operational challenge but also a potential safety hazard if not attended to appropriately.

In this scenario, it is not a case of one pump fits all dewatering application requirements and it is advisable to deal with a reputable pump supplier to ensure the most appropriate solution is selected, according to Integrated Pump Rental.

Lee Vine, Managing Director of the company, said each application requires a site-specific solution.

“There are numerous options available in terms of the actual pump and ancillary equipment, as well as the choice between rental and outright purchase,” he says. “The differentiator that our team offers is the ability to assess a given application and provide a pit dewatering solution with the correctly sized pump.”

There are several factors that can have an impact on the pump selection, and this includes available power sources; the volume of water to be pumped; and the condition of the dirty water, including size and type of particles in the water.

“What adds complexity to pit dewatering applications is that, in many cases, the need to dewater a pit can be urgent and customers are forced into making an incorrect pump selection or tying themselves into a contract that does not work in the longer term,” Vine says.

While the decision to hire or purchase is an important commercial one, so is the actual selection of the pump itself, he said.

“If the pump is not sized correctly for the dewatering application at hand, it will not perform as required. This, in turn, leads to further operational challenges including production losses and sometimes even the need to change the pump resulting in further costs.”

One of the most important factors to consider is the available energy source. If there is no access to power, options such as diesel-driven or pumps fitted with hydraulic power packs must be explored.

When selecting the pump, it is also important to understand the specifics of the water ingress conditions and whether this is a long-term issue or simply a short-term challenge. This scenario will dictate the pump size, its rated output and what ancillary equipment is required.

As an example, Vine points to a recent dewatering application on a mine in Lesotho where a constant flow of water into the mine’s pit area demanded that water be urgently and reliably pumped out.

Over time the pit depth had increased, and the groundwater level had been exacerbated by the winter snowfall in the highlands of the country. As a result, the total dynamic head for the duties of the installed dewatering pump installation changes and the mine required an urgent solution.

Initially a Sykes XH150 diesel driven pump was deployed, pumping at 120 l/s at 150 m head. Subsequent to this, a second Sykes pump was dispatched to site to ensure the level of water remained at an acceptable level.

With the two Sykes pumps on site, the mine was assured of enough pumping capacity, should the groundwater level increase.

The call from this mine came in and, within 24 hours, the first Sykes pump was installed on site, according to Vine.

“This is very significant, when one considers that the mine is situation some 500 km from the company’s front door and across the border into a neighbouring country.”

Integrated Pump Rental not only rents out Sykes diesel driven pump sets, the company is also responsible for the sale of these dewatering pumps across southern Africa. The robust units are designed for reliable performance, under even the harshest operating conditions, according to the company.

Integrated Pump Rental keeps its head during Lesotho mine dewatering project

Integrated Pump Rental says the quick deployment of its dewatering solution has allowed a Lesotho mine to keep operating as normal.

A constant flow of water into the mine’s pit area demanded water be urgently and reliably pumped out, according to the company. A fuel-efficient Sykes Xtra High Head pump set was chosen for the job, pumping into a 200 mm HDPE line with a head of 127 m to a holding dam.

According to Integrated Pump Rental’s Andre Strydom, timing was of the essence to the customer: “We secured this dewatering contract due to our quick and effective response. The Sykes XH150 unit was on site and commissioned just 24 hours after receiving the call from the customer.”

Strydom highlighted that, as mines and quarries go deeper, conditions require a solution like the Sykes XH150. With its automatic priming and solids handling capacity, it is designed to dewater more efficiently and effectively.

“The unit has one of the best shaft stiffness ratios of any automatic priming pump on the market,” he says. “Sykes engineers have ensured that the enormous pressures and heads associated with such performance do not compromise seal integrity through shaft flexing.”

All models have the ability to operate unattended at high discharge heads, with the pumps able to be primed with long suction hoses and the ability to manage suction lifts of up to 9 m.

“The units can even run dry for extended periods due to the oil bath mechanical seal assembly,” the company said. “Designed for robust and reliable performance with high volumes of water, Sykes pumps have an established reputation for the fast and effective control and removal of sub-surface water.”

The pumps can even operate in “snore” condition, Integrated Pump Rental says, which accommodates fluctuating suction levels. “In these conditions, the pump will snore until the liquid is available for the pump to fully re-prime itself automatically,” the company added.

Namakwa enlists FLSmidth pumps to cut downtime, costs at Kao diamond mine

The installation of a FLSmidth KREBS millMAX™ pump at Namawka Diamonds’ Kao mine, in Lesotho, is, according to the mining equipment maker, providing the miner with significant cost savings through increased impeller, casing and back liner wear life.

FLSmidth’s engagement at Kao started when the mine required a pump conversion in the field – an undertaking that can be difficult and time consuming, according to the mining OEM. “It is also a high-stakes operation as a cyclone feed is critical to the overall process and ability to generate returns. A wrong decision can mean a lot of lost revenue,” the company said.

It was the potential for cost efficiency that convinced Kao diamond mine to implement the KREBS millMAX Pump. After initial discussions, the first trial pump – a millMAX 8×6 centrifugal seal (C/S) – was installed in a cyclone feed application (DMS 2 pump 1).

Initial results after seven months showed the millMAX was performing extremely well on the wear side, according to FLSmidth.

“So, once you get the green light, you need to confirm the duty details and measure up the existing installation to ensure that when you begin to install the pump there are no surprises,” the company said.

Brad Moralee, Head of Product Unit Pumps, Cyclones and Valves at FLSmidth, said: “It’s high pressure for us: you are typically given a window of opportunity during a shutdown to complete the change, after which the new pump must run as expected when the plant is re-started.

“You need the combination of a great product but, more importantly, great technical understanding of the duty to be able to propose the correct solution. We understand what is at stake from the customer side.”

The change produced impressive results in comparison with the previous solution from another supplier, according to FLSmidth, with the millMAX increasing the wear life by nine times, across impeller, casing and back liner. “This has seen Kao make significant cost saving on direct replacement costs, reduced downtime and saved labour expenditure,” the company said.

While Kao mine operators were impressed with the benefits from the switch, a slight gland leakage was causing concern, according to FLSmidth. To resolve this, FLSmidth suggested running a one-month trial with the slurryMAX, which had just recently arrived on the South Africa market.

“The slurryMAX trial was based purely on its sealing capabilities as Kao were confident of the hydraulic performance of the pump and had no concern about wear as they were confident the slurryMAX would show predictable and even wear life across all wet-end parts,” the company said.

Kao’s confidence also came from the fact the slurryMAX design is based on the millMAX range, whose wear ring technology has created an efficient and long-lasting slurry pump.

The main difference between the millMAX and the slurryMAX is that the millMAX is an all-metal pump meaning it does not have an outer casing and an inner wear liner (the casing itself is made from the high chrome wear material), while the slurryMAX is a split casing design that has a replaceable inner liner. The purpose of this design is that multiple material liner options are available to fit in the same outer casing.

“The slurryMAX features an improved, more efficient impeller and an optional water drain plug for easier maintenance, allowing water that might have settled at the bottom of the pump to be drained quickly,” the company said.

Leigh Rieder, FLSmidth Sales Engineer, concluded: “Kao is extremely happy with the hydraulics and lack of excessive wear of our pumps, which has meant that their cost of ownership is low. We have recently received an order from the customer for two more slurryMAX pumps and they have expressed interest in our slurryMAX 6×4 and slurryMAX 10×8 pumps.”

Commissioning of Gem Diamonds’ PET and electric pulse technology pilot plant set for Q2

Gem Diamonds looks to be only a matter of months away from commissioning a pilot plant that could help reduce diamond damage at its flagship Letšeng mine in Lesotho.

In the company’s December quarter trading update, it said the $3 million pilot plant could reach the commissioning milestone at the end of the June quarter.

The plant is set to test out both positron emission tomography (PET) to identify diamonds within kimberlite prior to the crushing process, and electric pulse technology to liberate the diamonds at the operation.

During the company’s Capital Markets Day presentation last year, Gem Diamonds said it had carried out due diligence on the PET technology, a sensor-based sorting system that could be applied to scan kimberlite to identify the diamondiferous rocks.

The technical due diligence concluded that the physics of the PET technology applied in the minerals industry was sound and functional, the scalability challenges identified could be addressed in the development and engineering phase, and value engineering was required to optimise the material handling and associated capital expenditure.

In tandem with this, the company has looked at ways to liberate the diamonds identified by the PET technology without causing damage.

In collaboration with the University of Johannesburg, it has developed a non-mechanical crushing system that uses electrical power to break the kimberlite. During last year, a prototype of this electric pulse technology was developed and successfully tested in Johannesburg, with further testing at higher altitude already being carried out at Letšeng.

Gem said on its website: “The group believes that the advancement of these and other technologies to detect and liberate diamonds within kimberlite will change the future processing paradigm, with a commensurate increase in the overall profitability.”

The pilot plant is initially expected to process tailings as part of the development of these technologies.