Home Blog Page 243

Caledonia records over US$107 million in revenue

TEPE
-
0
Caledonia records over US$107 million in revenue

Victoria Falls Stock Exchange listed gold-focused miner, Caledonia Mining Corporation recorded a US$107.7 million revenue during the nine months ended 30 September 2023. The revenue is in line with the prior year’s performance, the company results for the quarter and nine months ended September 30 2023 shows.

According to Caledonia CEO Mark Learmonth gold production at the company’s Gwanda-based gold mine, Blanket Mine was at 55 244 ounces during the nine months ended 30 September 2023. The Mine produced quarterly gold production of 21 772 ounces, a new quarterly record for the mine and an increase of three per cent on the 21 120 ounces produced in the corresponding quarter of 2022.

He said net debt at the end of the Quarter was at US$3.2 million compared to US$ 2.9 million realised in the previous quarter.

According to Learmonth Notwithstanding the very strong operating cash flow in the Quarter, net cash and cash equivalents decreased in the Quarter due to the negative cash flows at the Bilboes oxides mine and the continued high level of capital investment at Blanket, principally on a new tailings storage facility.

He said a dividend of 14 cents per share was paid in July 2023, and a further dividend at the same rate of 14 cents per share was paid in October 2023, being the 40th quarterly dividend paid by the Company since it began paying dividends in 2013.

Gross profit in the Quarter according to Learmonth was US$ 14.1 million and EBITDA1 of US$ 15.5 million, 2.5 percent lower than the US$15.9 million in the third quarter of 2022.

He said Consolidated on-mine cost per ounce for the Quarter was at US$928 compared to US$ 734 per ounce in the comparable Quarter of 2022. He said the increase was mainly due to the high cost per ounce at the Bilboes oxide mine, which has subsequently been placed on care and maintenance. On-mine costs at Blanket were US$817 per ounce, an 11.3 per cent increase from the comparative quarter with the increase being due to higher labour and electricity costs.

“Production at Blanket in the Quarter was excellent: Blanket is now operating as expected having achieved record gold production in the Quarter. Management is exploring initiatives to further improve mining efficiencies and manage operating costs.

“The Bilboes oxide mine has been a disappointment and as a result of operating losses incurred at Bilboes it has been returned to care and maintenance with effect from 1 October, from October onwards, the monthly holding cost of Bilboes is expected to be significantly reduced to approximately $200,000c per month. In due course, the remaining oxide material will be mined and processed alongside the sulphide ore. This outcome has no bearing on the viability of the much larger sulphide project which was the reason for acquiring Bilboes.

“As previously announced, encouraging results were received during the Quarter from the ongoing underground drilling program at Blanket which currently targets the Eroica ore body. Initial results indicate that the Eroica ore body has better grades and widths than expected. These results indicate that there is additional mineralisation that may, in due course, be accessed using the current infrastructure and which should further extend the life of mine. Blanket continues to provide a solid foundation for the Company, providing us with a platform for our other growth projects in Zimbabwe.

“We continue to work on a revised feasibility study for the sulphide project at Bilboes which will consider updated commercial assumptions and will inform the most judicious way to commercialise the project with the objective of providing the best returns for investors. I look forward to providing an update on our progress in due course.” Learmonth said.

Caledonia to sell its 12MW solar plant

TEPE
-
0
Caledonia to sell its 12MW solar plant

Gold-focused mining company, Caledonia Mining Corporation says it has received an undisclosed offer from a global operator to buy its 12MW solar plant with the process of sale underway.

Hit by power cuts and an unstable grid, Caledonia’s Blanket mine had installed diesel power backup, but this has been expensive and unfriendly to the environment. In 2021, the company began building a solar farm next to the mine, after raising US$13 million from a share sale for the project.

The plant which was announced to be in operation exactly 12 months ago as Caledonia started generating electricity for its Blanket Mine, providing an alternative to unreliable and costly ZESA power, will be sold to the unnamed company as Caledonia wants to focus on mining and leave electricity generation to energy firms.

According to the company CEO Mark Learmonth, the solar plant is currently operating well and providing economic benefits for the Company extensively.

“The solar plant which was commissioned in early 2023 continues to operate well. The solar plant is owned by Caledonia rather than by Blanket and therefore the economic benefit arising from the solar plant has been realised in the consolidated all-in sustaining cost rather than the on-mine cost. An offer has been received from a global solar operator to buy the solar plant and the sale process is underway,” Learmonth said.

Blanket Mine

Blanket Gold Mine is a well-established Zimbabwean gold mine, which operates at a depth of approximately 750 meters below surface and produced approximately 55,000 ounces of gold in 2019. Blanket also holds brownfield exploration and development projects both on the existing mine area and on its satellite properties which are within trucking distance of the Blanket metallurgical recovery plant.

The Blanket Mine is located in the south-west of Zimbabwe approximately 15 km west of Gwanda, the provincial capital of Matabeleland South. Gwanda is 150 km south east of Bulawayo the country’s second largest city and 196 km northwest of the Beit Bridge Border post with South Africa, and 560 km from Harare, Zimbabwe’s capital city. Access to the mine is by an all-weather tarred road from Gwanda, which is linked from Beit Bridge to Bulawayo and Harare by a national highway.

Invictus reaffirms presence of moveable hydrocarbons at Mukuyu 2

TEPE
-
0
Invictus reaffirms presence of moveable hydrocarbons at Mukuyu 2

The prospect of finding commercially viable oil and gas in Muzarabani is almost within reach as the company reported that it discovered the presence of moveable hydrocarbons at Mukuyu 2 exploration well.

Rudairo Mapuranga

According to Invictus Energy‘s Managing Director Scott MacMillan, the exploration team successfully recovered natural gas (predominantly methane and trace heavier hydrocarbons) to the surface from the Pebbly Arkose formation and continued pipe-conveyed logging operations due to challenging borehole conditions.

He said wireline logging data from gamma-ray, density-neutron and resistivity has identified multiple hydrocarbon bearing intervals in the Upper and Lower Angwa reservoir sands, subsequently reaffirming the moveable hydrocarbons observed during initial fluid sample cleanup which showed gas and liquid hydrocarbons flowing through the onboard compositional fluid analyser (CFA). “Prior to the fluid sampling in the Pebbly Arkose formation,” MacMillan said, “analysis of the wireline logs interpreted the presence of residual gas (low gas saturation below the net pay cutoff). The formation was targeted to acquire a water sample to assist the calibration of resistivity data and calculation of gas saturation in the below Upper and Lower Angwa formations.”

According to MacMillan the recovery of natural gas to the surface from a primarily water-bearing interval in the Pebbly Arkose confirms the presence of hydrocarbons coupled with the wireline log interpretation of hydrocarbon-bearing reservoirs in the Upper and Lower Angwa formations and most importantly signifies a potential discovery in the Mukuyu field (as per Society of Petroleum Engineers Petroleum Resource Management 2018 definition section 2.1.1.).

“Further evaluation results continue to reaffirm the presence of moveable hydrocarbons at Mukuyu2, evidenced by the recovery of natural gas from the Pebbly Arkose formation and further wireline logging data interpretations obtained from the Upper and Lower Angwa reservoirs.

“Due to compounding sampling challenges, borehole conditions and well control measures the Company, in conjunction with our service providers, have determined a simple vertical sidetrack will provide the strongest opportunity to achieve our remaining Upper and Lower Angwa evaluation objectives.

“The Company is currently funded to conduct and evaluate the planned sidetrack operations, with the completion allowing the well to be suspended for future flow testing. I thank our shareholders for their patience as we conduct the sidetrack well and finalise the evaluation program, I invite you to attend the webinar briefing to discuss the initial results and forward plan,” MacMillan said.

Subsequent evaluation of the Upper and Lower Angwa

Higher than anticipated pressure in the gas leg in the Lower Angwa beneath 3,400mMD where formation pressures exceed 5,000 psi which required an increase in the mud weight to maintain control of the wel and preserve well barriers whilst drilling.

Connection gases were observed during the drilling of this part of the hole section to a Total Depth of 3,718mMD together with high levels of trip gas resulting in the implementation of well control measures through the raising of the mud weight to ensure the safety of the drilling and logging operations and maintain well integrity.

The raising of the mud weight has subsequently led to high overbalance conditions in the shallower intervals of this hoe section which has resulted in fluid losses and formation invasion by the drilling fluid which is evidenced by the high pump-out volumes required to obtain fluid sample cleanup to obtain representative reservoir fluid sampes. High amounts of overpul are required to free the drill string and wireline tools from several points along the well bore resulting in tool damage, together with hold-ups and obstructions in the wellbore is typically indicative of hole instability/breakdown.

Subsequent attempts to complete the fluid sampling program on pipe-conveyed logging in the Upper and Lower Angwa reservoirs and the remaining data acquisition program have been hampered by too many failures. This is primarily related to the conditions, borehole deterioration and compounded by the duration this hole section has been exposed since drilling of this interval commenced.

Due to the limited availability of replacement fluid sampling tools and the risk of successfully completing the fluid sampling and remaining data acquisition program in the current borehole, the Company has carefully considered all options to achieve our objectives for the Mukuyu2 well.

A thorough assessment in conjunction with our service providers was conducted and determined that plugging back the existing 8 ½ inch wellbore section and conducting a simple vertical sidetrack from the 9 ⅝ inch shoe (at approximately 1,966mMD) would provide the Company with the strongest opportunity of acquiring vaid fluid samples from the well.

Forward plan

The Exao Rig 202 is preparing to plug back the existing 8 ½” wellbore section and commence re-drilling the 8 ½” hole section with more optimal parameters to approximately 3,400mMD above where the overpressure zone in the Lower Angwa commences. The Mukuyu-2 vertical sidetrack will be more conducive for conventional wireline logging operations including the fluid sampling to be conducted in the Upper Angwa and part of the Lower Angwa reservoirs, providing parameters for a more efficient and economic sidetrack operation in comparison to the Mukuyu-1 sidetrack well.

The completion of the sidetrack will also allow for the well to be suspended for future flow testing through running the 7 inch liner over this interval and retain the ability to drill, evaluate and test the remaining portion of the Lower Angwa in 6 inch hole in future operations.

Following the conclusion of the drilling of the 8 ½ inch hole section, the well will be logged including wireline formation testing and final results provided. The Company anticipates the remaining activities to conduct the sidetrack and wireline logging to take approximately 2128 days depending on drilling and logging conditions and is currently funded to complete these activities.

Caledonia COO Dana Roets to step-down

TEPE
-
0
Caledonia COO Dana Roets to step-down

Caledonia Mining Corporation Plc has announced that Chief Operating Officer (COO) Dana Roets will step down from his role on February 29, 2024. However, Roets will remain a director of the company and its subsidiaries until that date.

Roets joined Caledonia as COO in 2013 and has played a significant role in the development of the business over the past decade.

During his tenure, the Caledonia’s production increased from 45,000 ounces to over 80,000 ounces in 2022. In the most recent quarter, ended September 30, 2023, the Blanket Mine achieved record quarterly production of nearly 21,800 ounces. Additionally, the group’s all-in sustaining costs decreased from $978 per ounce to $878 per ounce over the same period.

One of the key factors contributing to Caledonia’s success in the past decade was the successful implementation of the Central Shaft project. Under Mr. Roets’ direction, the company sank a six-meter diameter shaft from the surface to 1,204 meters.

The project was accomplished using internal financial and technical resources and was completed without any fatalities. It also significantly extended the mine-life of Blanket Mine, a Gwanda based gold miner.

Furthermore, the resumption of deep-level exploration at Blanket in early 2023 has shown promising results, which are expected to further extend the mine’s lifespan.

In light of Mr. Roets’ impending departure, Caledonia has already begun the process of identifying a suitable candidate for the COO position.

Commenting on the announcement, Caledonia Mining Chief Executive Officer, Mark Learmonth,  expressed his appreciation for Roets’ contributions over the past decade. Learmonth highlighted the increased production, reduced costs, and exploration success achieved under Roets’ leadership. Learmonth also mentioned significant milestones, such as the operational solar plant and the construction of a new tailings storage facility.

“Dana has made an outstanding contribution to Caledonia over the last ten years – as evidenced by the increased production, reduced costs and exploration success which we believe will, in due course, extend Blanket’s life of mine. This was achieved against the backdrop of a challenging operating environment and the COVID-19 pandemic which introduced a new set of unanticipated operational challenges,” Learmonth said.

“Dana is leaving the business not only having seen Blanket Mine hit its long-term target of 80,000 ounces (in 2022), but also with an operational solar plant providing around a quarter of Blanket Mine’s daily electricity requirements, thereby reducing our dependence on diesel generators. More recently, he has overseen the construction of the first phase of a new tailings storage facility which, when fully built, is expected to serve the mine for at least the next fourteen years at the current production rate.

“Along with the board and his colleagues, I would like to thank Dana for his contribution and we wish him well in his future endeavours,” Learmonth concluded.

Crack down on Non Compliance – gvt suspending Mining licenses

TEPE
-
0
Crack down on Non Compliance – gvt suspending Mining licenses

The government of Zimbabwe has taken the action to suspend mining licenses for Mining Operations who are not complying with mining laws.

The move comes as part of President Mnangagwa’s initiative, the “Responsible Mining Audit“ which aims to promote responsible and compliant mining activities in the country.

The audit was implemented to ensure that all mining activities are carried out responsibly and in accordance with Zimbabwe’s legal framework.

During a recent Post Cabinet Press Briefing, Minister of Information, Publicity, and Broadcasting Services, Dr Jenfan Muswere, announced that the government had received and adopted a report on the “Responsible Mining Audit” as presented by the newly appointed Minister of Mines and Mining Development, Hon Zhemu Soda.

“Regarding Small Scale Mines, with a labour force of up to 200 employees, the audit established that most of them are not complying with the legal transportation and licensing issues.

“The nation is being informed that in all the identified transgressions, corrective action is being taken including the following:

  1. Imposition of fines,
  2. Confiscation of explosives,
  3. Suspensions from operating licences,
  4. Cautions with instructions to regularise within a stipulated time-frame.

The Responsible Mining Audit came up with a number of useful recommendations which Government is implementing and the Interministerial Committee should continue to develop other solutions,” said Dr Muswere.

Dr Muswere also highlighted the positive compliance of large-scale mines usually referred to as Primary Producers, with at least 1,000 employees.

These mines were found to be mostly complying with mining laws, environmental laws, regulations by Zimbabwe Revenue Authority, Immigration, labor, and energy sectors. However, there were a few isolated cases where immigration laws were being violated.

“The nation is being informed that large scale mines, with at least 1 000 employees, are to a large extent, complying with mining laws, environmental laws, Zimbabwe Revenue Authority, Immigration, labour and energy regulations. There are however isolated cases where immigration laws are being violated, said Dr Muswere.

On the latter, some Chinese operations have flouted immigration laws.

Speaking earlier this year, Minister Soda said the report is well written and recommendations well spelt out as the Ministry of Mines had an opportunity to visit over 400 ASM-run mining sites to compile the report.

“On the 10th of May HE launched the responsible mining initiative. Following the launch the Ministry then conducted a responsible audit of our mines. About 422 sights were visited and a report has since been compiled and it will soon be tabled before the cabinet. It is that report which will inform the government on the next steps that need to be taken, to also give protection and assistance to the small-scale miners but our desire is whenever mining is taking place let’s put safety first,” Minister Soda said.

Objectives of the Responsible Mining Audit

The objective of the Initiative is to ensure that all mining operations are conducted in accordance with the country’s laws. The audit team will comprise members from the following Ministries, Departments and Agencies, Mines and Mining Development, Lands, Agriculture, Fisheries, Water and Rural Development, Local Government and Public Works, Energy and Power Development, Environment, Climate, Tourism and Hospitality Industry, Departments of Immigration and Labour, the Zimbabwe Revenue Authority, the Environmental Management Agency, and the Zimbabwe Republic Police,” Mines and Mining Development Minister said in a statement.

ZACC arrests MashEast Mines Inspector for extortion

TEPE
-
0
ZACC arrests MashEast Mines Inspector for extortion

The Zimbabwe Anti-Corruption Commission (ZACC) yesterday arrested and charged an official from the Ministry of Mines and Mining Development in Mashonaland East with extortion.

Antony Singende, the Provincial Mines Inspector for Mashonaland East Province, allegedly demanded a substantial sum of money from Mine Manager Virimai Nyamvura in exchange for maintaining a valid blasting license.

Virimai Nyamvura, a mine manager at Koodoo 83 Mine, owned by a Mr Emmanuel Ndemera, was suspended from work on October 7, 2023. The work-related suspension lasted for 21 days before being revoked on October 20, 2023. Shortly after his return to work, Singende, the accused Mines Inspector, paid a visit to Koodoo 83 Mine and made alarming demands.

Singende demanded a sum of US$150.00 for re-endorsement of Nyamvura’s blasting license which had lapsed during the latter’s suspension. Furthermore, he insisted on an additional US$200.00 to prevent the withdrawal of Nyamvura’s blasting license. Singende subsequently ordered Nyamvura to bring the money and the blasting license to his office on November 17, 2023.

Reporting the Crime

Nyamvura reported the matter to his employer, who recommended contacting the Zimbabwe Anti-Corruption Commission. Acting on this advice, Nyamvura promptly filed a report with the commission on November 16, 2023. An investigation ensued.

Arrest and Evidence

On November 17, 2023, Nyamvura adhered to Singende’s instructions and handed over US$350.00 trap money. Singende was arrested after receiving the money, which was subsequently recovered as an exhibit. Moreover, a search of Singende’s person revealed an additional US$1,600 that he failed to account for, casting further suspicion on his criminal activities.

Legal Consequences

Singende was charged with extortion, as defined under section 134 of the Criminal Law Codification and Reform Act Chapter 9.23. This charge carries significant penalties and could potentially result in a substantial prison sentence if proven guilty. Singende appeared at the Harare Magistrates Court for his initial hearing on the matter. Singende was remanded in custody and his case was postponed to the 20th of November 2023.

Prosecutor arrested for soliciting a us$20k bribe to secure a reduced sentence for Rushwaya

TEPE
-
0
Prosecutor arrested for soliciting a us$20k bribe to secure a reduced sentence for Rushwaya

A Harare public prosecutor Pardon Dziva was arrested for allegedly soliciting a US$ 20,000 bribe from the sister of Henrietta Rushwaya to facilitate a lighter sentence for the former by presiding judge Justice Pisirayi Kwenda.

Dziva (30) claimed she could get a favourable sentence at the High Court after he misrepresented that he was a runner for Justice Kwenda.

Ironically Rushwaya did get a “light sentence” after escaping jail for trying to smuggle 6kgs of gold to Dubai.

Dziva who is being charged together with Alexio Tombe (37) appeared before magistrate Ngoni Nduna.

The duo were remanded in custody to Monday for bail application.

The complainant is Helliate Rushwaya a former Non-Executive Board Member at the Zimbabwe Broadcasting Corporation (ZBC). She is Henrietta’s young sister.

Henrietta’s smuggling case was before Justice Kwenda at the High Court in Harare awaiting sentence on 15 November 2023 at 1430 hours.

lt is alleged that on the same day November, the informant Fungai Mangizvo received a call from Wellington Takavarasha who is a workmate to Henrietta Rushwaya.

The complainant instructed her niece to tell Takavarasha to contact her which he did.

Takavarasha contacted the informant and stated that he had been approached by Progress Maringamoyo who indicated that he was in a position to facilitate the passing of a lighter sentence in Henrietta Rushwaya’s case.

It is alleged that on the same day, Maringamoyo called Takavarasha and offered to link him to Dziva who claimed to be Justice Kwenda’s runner.

Takavarasha and Maringamoyo went to the Harare Magistrates Court where they met Dziva and Dziva demanded US$30 000-00 to facilitate the deal.

The figure was subsequently negotiated down to US$ 20,000-00.

Takavarasha informed the Informant that Dziva requested US$ 20,000. The informant managed to raise US$ 10,000-00 and reported the matter to the CID Police Anti-Corruption Unit where a trap was set.

They agreed to meet at the CABS Centre at the corner of Jason and Sam Nujoma Street, Harare.

Upon arrival at CABS Centre, Tombe approached the informant who was in the company of a detective and confirmed that he was sent by Dziva to take them where Dziva was. Tombe indicated that the complainant should drive to the basement of CABS Centre and she refused.

The informant suggested meeting at Meikles Hotel but Tombe suggested meeting at Kebab Restaurant in Milton Park.

The informant then proceeded to Kebab Restaurant driving between Dziva who was driving a Toyota Camry whilst Tombe was seated in the back seat in Helliate Rushwaya’s car.

Upon arrival at the agreed place, Dziva went into Informant’s car where he received US$10 000-00 in the presence of the detective and Tombe.

Dziva was arrested and the trap money was recovered. The trap authority and the recovered trap money will be produced in court as exhibits.

Source: Nehanda Radio

BREAKING: Abel Makura appointed AMMZ President

TEPE
-
0
BREAKING: Abel Makura appointed AMMZ President

Engineer Abel Makura has been appointed President of the Association of Mine Managers of Zimbabwe (AMMZ).

At a colourful ceremony currently underway in Victoria Falls Makura was announced President replacing Caledonia Mining’s Elton Gwatidzo.

Pickstone Peerless General Manager Alfred Madowe will deputise Makura.

The following where also announved as the Council Members

George Waeni
Cloete Munjoma
Larnston Gowera
Ray Chiridza
Coburn Katanda
Gift Mapakame
Walter Madzimure
Tirivashe Eddington Vere

More to follow…

Emerging World Trends That Will Impact on the Decision Process of the Future Mine Manager – Walter Nemasasi

TEPE
-
0
Emerging World Trends That Will Impact on the Decision Process of the Future Mine Manager – Walter Nemasasi

The role of a Mine Manager is continually evolving as the world around us changes. Rapid technological advancements, volatile economic environments, politically unstable periods, and the rising influence of civic organizations and NGOs are just a few of the factors that Mine Managers must take into account when making decisions for their operations, General Manager of Unki Mines Engineer Walter Nemasasi said in a presentation at the on-going Association of Mine Managers of Zimbabwe (AMMZ) AGM and Conference 2023.

His presentation explored some of the emerging world trends that will impact the decision process of the future Mine Manager.

Below is a summary of his presentation

One of the key trends in the mining industry is the call for responsible mining. Organizations like the Initiative for Responsible Mining Assurance (IRMA) have set standards and requirements for responsible mining practices, covering areas such as legal compliance, stakeholder engagement, environmental management, and worker health and safety. Mine managers must navigate these requirements to ensure that their operations align with responsible practices and maintain their license to operate.

Another trend that Mine Managers must consider is the increasing focus on zero environmental damage and zero injury to people. This means adopting sustainable and environmentally friendly practices, such as using clean sources of power like renewable energy and optimizing energy use. It also means implementing advanced safety systems, such as proximity detection systems and real-time remote monitoring, to ensure the safety of workers.

Technological advancements are also reshaping the mining industry. From drilling and excavation to processing and transportation, machines and equipment are becoming more autonomous and efficient. Remote-controlled and autonomous machines are reducing the need for manual labor and increasing productivity. Robotics, powered by artificial intelligence, are being used for tasks like drilling, blasting, loading, and conveyance. These advancements not only increase efficiency but also improve safety by keeping workers out of potentially hazardous areas.

The convergence of wireless technologies and mining is another trend that mine managers must be aware of. The Internet of Things (IoT) is transforming the way mining operations are managed. Through the use of micro-electromechanical systems and internet connectivity, mine managers can monitor and control their operations remotely. This not only improves productivity but also removes operators from potentially dangerous work areas.

In addition to technological advancements, mine managers must also consider the impact of global trends on metal prices and inflation rates. Fluctuating metal prices can greatly impact the profitability of mining operations, while high inflation rates can increase operating costs. Mine managers must stay informed about these trends and adopt agile strategies to navigate the volatile economic environment.

The article also touches on specific projects and technologies that are being developed and implemented in the mining industry. For example, the nuGen Zero Emissions Haulage Solution (ZEHS) truck, a hydrogen-powered vehicle, is being launched to reduce CO2 emissions. Processing technologies, such as online analyzers and the Kell hydrometallurgical process, are improving plant control and efficiency while reducing energy consumption and CO2 emissions.

Tailings storage facilities (TSFs) are also undergoing changes in management practices following the Brumadinho dam disaster in Brazil. More attention is being given to biodiversity monitoring using eDNA techniques, which analyze DNA traces left by living organisms in the environment. This allows for the identification of existing and historical species in an area, helping to protect biodiversity.

Overall, mine managers of the future must be proactive in staying ahead of emerging world trends. They must prioritize responsible mining practices, leverage technological advancements, and adapt to changing economic and environmental conditions. By doing so, they can ensure the viability of their mines and contribute to a greener and more sustainable world.

GET Unki Mines General Manager Engineer Walter Nemasasi’s PRESENTATION HERE

 

How electricity is generated at units 7 and 8 in Hwange

TEPE
-
0
How electricity is generated at units 7 and 8 in Hwange

The Association of Mine Managers of Zimbabwe (AMMZ) yesterday was on a technical visit at the Zimbabwe Power Company (ZPC) to learn more about the power generation at the newly installed units 7 and 8 of the Hwange expansion project.

The team was briefed on how power is generated at the Power plant by the Acting Facility Site Manager Lucia Chibanda said her team is responsible for units 7 and 8 which have an installed capacity of 670 megawatts. The team also toured the Mega facility which is much bigger than any current operating mine in Zimbabwe.

Briefing the AMMZ members Chibanda said, to support power generation, the project includes a water pipeline spanning 42 kilometres from Deka and a new reservoir with a capacity of 250,000 cubic meters. The water is treated using reverse osmosis, ultrafiltration, and demineralization processes to ensure it is pure and free from minerals that could cause scaling in the boiler tubes. The treated water is then heated in the boiler using coal as the fuel source. The steam generated from the heated water rotates the turbine, which in turn produces electricity through generators with magnetic fields.

“In terms of power generation. Our key input is water, which comes from Deka. We built a new reservoir up there. It has a capacity of 250,000 cubic meters to hold water. That’s for approximately six, five, five days. So it is pumped to our reservoirs. From the reservoirs, we’ve got underground pipelines that we installed. We go to the raw water. Basically, raw water is treated. We’re just adding chlorine. It will be now safe to drink.

“We bring it to this building that is just behind you. We call it the chemical water treatment plant. There, we have three different types of treatments. We’ve got reverse osmosis. We’ve got ultrafiltration. Then we’ve got demineralization. What we are simply trying to do is remove all the minerals in the water to make it as pure as possible. We actually make it more pure than the bottled water that we drink, so that we avoid scaling in our boiler tubes.

“From here, the water is pumped to the boiler. We’ve got various auxiliaries that you see when you go through the plant, mainly on the ground floor. These are boiler feed pumps, condensate pumps, cooling water pumps, etc. Our water goes to the boiler. That’s where it’s heated to temperatures of 541. We increase pressure to about 167 bars. That’s almost 80 times the pressure in your vehicle tires.

“Then we have superheated steam. Our turbines use superheated steam, different from Kariba, which uses water. That’s why that water that is stored in the dam, you get the issues of water levels. Here, we use steam, which is generated from water that is heated. But for us to be able to heat the water in the tubes, we need coal. That’s our fuel source. So we have coal that comes from the coal miners. We have a coal stockyard. It’s conveyed through the conveyance system, which are basically belts. Then we have a bank, how we can store it.

“It goes to the mills. I’m sure those who come from the mines will appreciate how a mill works. We grind the coal to fine powder. It’s pushed by air, which is sucked through our fan or draft system. We’ve got big fans, the forced draft fan and the induced draft fan. The air pushes the fine powder, the coal, and it ignites. We have a fireball inside our boiler. You won’t be able to see it on the boiler. The tubes are all encased inside, and they’re insulated,” Chibanda explained.

Once the steam has done its work, it is cooled back into water using cold water from the reservoir. The cooling process takes place in a cooling tower, allowing the water to be reused in the closed cycle of power generation.

“Hot water becomes steam. Superheated steam goes to the turbine. On the turbine, what we basically want is mechanical energy. We want to rotate the turbine. Once the turbine is rotating and we have magnetic fields, that’s how we produce electricity. This is done by the generator.

“There’s a magnetic field that is in the generator and when the shaft, which is coupled to the turbine, rotor is rotating, we produce electricity. Then we have got transformers. Those ones will be outside the plant. You want to step up, would have generated electricity at 20 kVA. But when we transmit it, we need to transmit it at a higher voltage. That’s the 400 and the 330. So we then use the different transformers that we have to step it up.

“Then in terms of the steam. The steam that has done work, it’s a closed cycle, based on the Rankine cycle or the thermal cycle. We want to use that water again. So we cool the steam back to water. We use cold water, which is from the raw water reservoir. We cool the steam. It becomes water again. That water which has cooled the steam, we take it to the cooling tower, which is, I think, the most popular shape for anything. The one with the Venturi shape that you see is the one where water is cooled, and it becomes cold again. And then you see water vapour escaping from the top of the cooling tower. I would say in a nutshell, that’s the basic process of how we generate electricity,” Chibanda concluded.

The AMMZ is currently on day two of its AGM and conference. The first day saw Zimplats’ Ngwarati Mine winning the AMMZ SHE Audits scoring 97% ahead of Mupfuti’s 94%.

Both Ngwarati and Mupfuti reported zero fatalities, zero Total Recordable Injury Frequency Rate, zero Lost Time Injury Frequency Rate, and zero Lost Time Injury Severity Rate.

1...242243244...686Page 243 of 686