URUMQI, Oct. 27 (Xinhua) -- Four hours south of Hami, after a long drive across the barren Gobi Desert of northwest China's Xinjiang Uygur Autonomous Region, a sweep of blue-green water appears on the horizon.
It is not a lake. These are evaporation ponds, stretching across more than 160 square kilometers at a sprawling potash operation in Lop Nur, once known as the "sea of death" for its extreme aridity and forbidding terrain.
The desert is also home to Lop Nur Town. There are no families who have lived there for generations -- nearly everyone went there in the new century because of the potash resources beneath Lop Nur's salt crust.
POTASH BENEATH DESERT
Potassium is a key plant nutrient, helping crops develop stronger stalks and fuller grain. For years, China had relied heavily on overseas potash, with domestic self-sufficiency long below 30 percent.
Exploration in the 20th century uncovered a world-class sulfate-type potassium-rich brine deposit in northern Lop Nur. But finding the resource was one thing, and producing fertilizer from it on an industrial scale was another.
There was no established industrial process elsewhere to copy. The location also posed its own problems. Two decades ago, there were no roads, little fresh water and no settled population.
"When I first came to Lop Nur, the wind blew sand straight into the face. You could go through all four seasons without seeing any green," said Liu Qinyong, who has worked at SDIC Xinjiang Luobupo Potash Co. Ltd. for more than 20 years. "Everything had to be brought in from outside." SDIC is short for the State Development and Investment Corporation.
The first batch of Lop Nur-brand potassium sulfate was produced in 2003. The company later built a production complex with an annual capacity of 1.2 million tonnes, which reached designed capacity by the end of 2011.
The company has so far produced over 27 million tonnes of potassium sulfate, with its products accounting for nearly half of China's potassium sulfate market.
TURNING HARDSHIP INTO ADVANTAGE
Production in Lop Nur relies heavily on both evaporation and time.
Brine pumped from underground moves through a four-stage evaporation system, where different salts crystallize as the concentration increases. It takes nearly two years before potassium-bearing minerals are ready for processing. These minerals then undergo further processing, including purification, crystallization and drying, to produce potassium sulfate.
The extreme evaporation that makes Lop Nur so inhospitable does much of the concentrating naturally.
Water scarcity has also shaped the production system. Fresh water has to be piped in from Ruoqiang, about 240 kilometers away, while liquids left from processing are recycled within the system and brine is not discharged outside it.
Inside the plant, progress has often been measured in fractions of a percentage point.
Dong Guangfeng, head of the potassium sulfate plant, arrived in 2005, when there was only an industrial pilot facility. Over the following two decades, he and his colleagues worked to raise potassium content and develop a wider range of products.
The potassium oxide content of the company's potassium sulfate has risen from 51 percent to a stable 52.5 percent, while a high-end product reaches 53.8 percent. Its product range has also expanded to include granular and water-soluble fertilizers.
China's potash self-sufficiency has now risen to around 50 percent, Dong said, with Lop Nur contributing an important share of domestic supply.
The brine is also yielding another product. In 2023, the company put into operation a line that extracts lithium from residual brine after potash production. The facility can produce 5,000 tonnes of lithium carbonate a year, mainly for use in power batteries for new energy vehicles.
A TOWN TAKES ROOT
The industry has also drawn people.
Chen Liangzhi, from southwest China's Sichuan Province, was among the early arrivals. When he came to Lop Nur in 2000, there were no roads, electricity or running water.
He lived in a semi-underground shelter and ran a restaurant from a prefabricated metal room. At midday in summer, when surface temperatures could reach 50 to 60 degrees Celsius, the room became too hot for cooking. Chen would retreat underground and wait until late afternoon before lighting the stove again.
Today, his restaurant covers more than 100 square meters and serves business travelers.
Lop Nur Town was formally established in 2002. Its water, electricity and heating are largely supplied via facilities operated by the potash company, while garbage and sewage are handled through shared facilities. Medical workers from the People's Hospital of Bayingolin Mongolian Autonomous Prefecture are stationed at the local clinic.
"If you want people to stay, you first have to make them feel secure about living here," said Liu Xiangyu, deputy Party secretary of Lop Nur Town. Over 3,000 people now live in the settlement that grew around the potash industry.
Notably, far beyond Lop Nur, potassium from beneath its salt crust is reaching and nourishing farmlands across China. ■
