NEW TECHNOLOGY AT ANGLO AMERICAN PLATINUM’S SULPHUR DIOXIDE ABATEMENT FACILITY

Murray & Roberts Power & Energy was awarded the contract to install a sulphur dioxide abatement facility to treat electric furnace off-gas for Anglo American Platinum at its smelter in Limpopo Province, South Africa.

The project was awarded late November and the team has been mobilised to site with the construction of the works camp. Anglo American Platinum is implementing new wet sulphuric acid (WSA) technology at the Polokwane smelter in order to reduce sulphur dioxide levels by an estimated 96%. This is in line with the Department of Environmental Affairs New Emissions Standards for sulphur dioxide.

The WSA process used at the facility diverts furnace off-gas from the main stack to a new secondary gas cleaning plant where any remaining dust and other impurities which can poison the catalyst used in the second step are removed. During the second step the sulphur dioxide in the off-gas is converted into sulphur trioxide which then reacts with the water present in the gas to form gaseous sulphuric acid which gives the process its name – wet gas sulphuric acid. The gaseous sulphuric acid is condensed to form liquid sulphuric acid which leaves behind a clean gas stream which meets emission standards.

In the last stage the cooled sulphuric acid is sent to a storage tank where it is shipped to market. The clean gas is discharged into the atmosphere.

Says Michael Neves, project manager at Murray & Roberts Power & Energy, “We are excited to be working on this project which is the first time that WSA technology is being used in the platinum group metals environment.”

The anticipated project completion date is in April 2020. The Department of Environmental Affairs new emission standards for sulphur dioxide stack emissions come into effect in 2015 with stack emissions limited to 3,500 Nm3 and a further reduction to 1,200 Nm3 by 2020.

MURRAY & ROBERTS POWER & ENERGY ON SITE AT SAPPI SAICCOR VULINDLELA PROJECT

Murray & Roberts Power & Energy has been awarded the erection contract for the Recovery Boiler and Secondary Recovery Unit at Sappi’s Saiccor Mill, part of Sappi’s Vulindlela expansion project.

The contract includes the erection of steelwork, pressure parts, prefabrication and erection of the ducting in both carbon and stainless steel, prefabrication and erection of the Secondary Recovery vessels pipework and the erection of the mechanical equipment.

The Recovery Boiler will be erected using a large tower crane brought in from the UK, with a capacity for lifting 12 tonnes at 50 metres, and standing 79 metres tall. The erection of the Secondary Recovery Unit will use a 600 tonne crawler crane.

The contract was awarded in November 2018 and was won against both local and overseas tenderers.

The Sappi Saiccor Mill produces dissolving wood pulp which is then used to manufacture a wide range of consumer products, in particular, viscose staple fibre which is used in clothing and textiles. The dissolving wood pulp supplied by Sappi is produced primarily from Eucalyptus hardwoods, a natural and renewable resource. Sappi is the world’s largest manufacturer of dissolving wood pulp with two mills in South Africa and one in North America.

Sappi’s Vulindlela project includes a R2,7 billion capacity expansion project and a further planned R5 billion over five years on continuous improvement initiatives and upgrades eventually increasing the mills production from 780 000 tonnes to 890 000 tonnes per year.

The Recovery Boiler and Secondary Recovery Unit will contribute to environmental and cost saving targets through a reduction in landfill waste by 48%, a cut of 50% to CO2 emissions, a 17% increase in water-use efficiency and a 35% reduction in SO2 emissions. Cost savings will amount to approximately R300 million per year.

The project site was established in January 2019 with an expected contract completion date of February 2020.

FOOD CHAIN REACTOR TECHNOLOGY OUTPERFORMS AT VERULAM

The Murray & Roberts Water Organica Resource Recovery Demonstration Plant is being operated at the Verulam Wastewater Treatment Facility in eThekwini. The purpose of the plant is to demonstrate the Organica Water Food Chain Reactor (“FCR”) Technology in South Africa and how it compares with existing technology such as Conventional Activated Sludge (“CAS”) which is in use at the Verulam facility.

Organica Water is a global provider of innovative solutions for localised treatment and recycling of wastewater. Murray & Roberts Water has the exclusive licence for the Organica technology in South Africa.

The Verulam plant receives wastewater from both domestic and industrial sources resulting in an influent of high strength and variable composition. The current operational status reports for the demonstration plant indicate that the removal efficiencies for the FCR technology is comparable to that of the CAS technology used in the Verulam facility with substrate loading and removal rate per unit of reactor volume higher for the demonstration plant. These statistics demonstrate that wastewater can be treated in smaller reactors with FCR technology in comparison to traditional CAS technology, MARCH 2019 / ROBUST 11 providing benefits to the surrounding communities including a smaller physical footprint for a wastewater treatment facility, reduced costs and an odourless fully enclosed system.

The demonstration plant was opened in April last year and will shortly be undergoing a few modifications. The modifications will include the removal of the greenhouse louvres to allow some of the humidity in the greenhouse to escape, improving the conditions for the tropical plants as well as the operators and technical team based at the facility.