This year, the theme of World Water Day is reducing and reusing wastewater. A prime example of how this can be done in mining is playing out at the Jabal Sayid mine in Saudi Arabia. The mine—a 50-50 joint venture between Barrick and Ma’aden, a Saudi Arabian state-run mining company—processes copper concentrate using 100 percent wastewater.
In fact, Jabal Sayid was one of the first mines in Saudi Arabia to sign a contract with the state-run National Water Company for the use of wastewater. As part of the agreement, the National Water Company allocated an 8,000 square-meter area at its sewage water treatment plant in Medina for a pumping station that is owned and operated by the Ma’aden Barrick Copper Company, the entity that operates Jabal Sayid. The Ma’aden Barrick Copper Company uses the pumping station to load treated wastewater on to trucks for transport to Jabal Sayid.
“We don’t use any fresh water in the mining process, and no water ever leaves the mine.”
“Jabal Sayid is unique because of the way it respects water,” says Basie Maree, the mine’s General Manager. “We don’t use any fresh water in the mining process, and no water ever leaves the mine.”
Globally, over 80 percent of the wastewater generated by society flows back into the ecosystem without being treated or reused, according to information in this year’s UN World Water Day fact sheet. It is against this backdrop that UN Sustainable Development Goal 6.3 calls for the world to improve water quality by halving the proportion of untreated wastewater by 2030. “There are many treatment processes and operational systems that will allow us to use wastewater to meet the growing water demand in growing cities, support sustainable agriculture, and enhance energy production and industrial development,” the UN World Water Day fact sheet says.
At Jabal Sayid, the Ma’aden Barrick Copper Company uses a Barrick-patented method to process copper concentrate. Unlike most conventional flotation methods, the process does not require cyanide, lime or fresh water. It instead uses oxygen and metabisulfate, a chemical reagent, to separate and concentrate copper from the waste particles contained in the ore at Jabal Sayid. The method, known as the air-metabisulfate process, is particularly well-suited for water scarce regions like Saudi Arabia because it can work in salt water, brackish water, and of course, wastewater.
“We are one of the only mines in the world that uses this innovative process and, as a Saudi national, I am very proud of that,” says Sami Maddah, Manager of Corporate Relations and Business Development for the Ma’aden Barrick Copper Company. “I do think that Jabal Sayid’s success with the air-metabisulfate process will encourage other companies to adopt similar mining methodologies.”
Jabal Sayid recycles as much wastewater as possible by recovering water contained in mine tailings, the waste materials left over after the copper concentrate is removed from ore. This is done via a filtration circuit housed within the mine’s processing plant. An estimated 70 percent of wastewater is recycled.
Because mine tailings are dewatered in the processing plant, the method of tailings storage used at Jabal Sayid is a relatively rare method known as dry stack tailings. Unlike conventional tailings storage facilities, which occur in large ponds that require the construction of complex tailings dams to store wet tailings, dry tailings are easier to maintain. They are compacted and stacked in tailings storage facilities lined with high density polyethylene. Management of the facility is far less complex due to the relative absence of water.
“Conventional tailings facilities normally have a large water footprint and there is greater potential for impacts on geohydrology and this must be managed and closely monitored at all times, including after a mine closes,” Maree says. “We certainly engage in rigorous water management and monitoring at Jabal Sayid, but because we don’t use hazardous chemicals in mine processing, and because there is very little water in our tailings storage facility, we will not face the same costs and complexities that most other mines incur when they close.”
In addition to using treated sewage water from Medina, Jabal Sayid also treats sewage water from the mine village, which is home to about 1,300 people, including direct employees of the mine and third-party contractors. Some of this water is used for mine processing and some is used to irrigate vegetation within the village.
“Over the years, our people have done a good job of planting trees in the mine village, and that is all serviced from this treated sewage water,” Maree says. “It doesn’t cost us anything and this has made a big difference to the appearance of the village. You should see it now. It’s like an oasis.”