Rahco International Inc., the longtime Spokane industrial manufacturer, says it has landed a contract to supply two more of its salt harvesters to a Chinese maker of potash for fertilizers. The contract is worth roughly $10 million.


Meanwhile, Rahco has signed an agreement in which Denver-based NexGen Highwall Mining Systems LLC will market new high-wall extraction equipment that the Spokane company has developed for the coal-mining industry. Under that contract , the first equipment is expected to be delivered to a West Virginia mine this spring, though Rahco already had landed its first order for a high-wall mining system on its own in January, before the marketing agreement was signed. That sale was to an Indonesian mining company. Such systems sell for more than $5 million each.


The new business, as well as other ongoing contracts, has required Rahco to hire about 20 new employees since early December, giving it about 170 workers currently. Most of those new hires have been engineering professionals, Rahco spokesman Dennis Medina says.


The salt harvesters Rahco is making are for Qinghai Salt Lake Industry Ltd., and are part of a major expansion of a potash operation in northwestern Chinas Qinghai province. Qinghai Salt Lake is a major producer of potash in China. Potash is a common component of fertilizer.


Rahco has made such harvesters for years, and previously has sold two others for the Quinghai operation. The machines harvest salts from the brine sediments of shallow lakes. Each harvester to be built under the contract will be capable of producing 700 cubic meters per hour of chemical salt slurry that will be transported to a nearby processing facility.


It will take Rahco about two years to build the machines, after which it will supply on-site supervisors to work with a Chinese team to install them.


The high-wall mining system Rahco has developed is used for a certain type of coal mining in which coal is extracted from the high walls left after pit mines have been mined out using conventional methods. Rahco had dabbled in the design of that type of equipment for years, but only last year decided it had come up with a cost-effective system.


Its first sale, to Jakarta-based PT Gunung Bayan Pratama Coal, will be used on the island of Borneo. The system Rahco developed can bore a narrow hole into the side wall of an open pit mine in order to recover coal reserves that previously would have been left behind because they were too costly to remove. The hole, called a seam, can be as little as 38 inches tall and as much as 1,500 feet back into the wall, Rahco says. The device will operate from a mining platform situated on the pit wall, and will include a continuous-digging device, a loader, and a series of self-propelled conveyor-belt cars to deliver materials to the surface. The system for the Indonesian mine, which is expected to be operational late this year, will have the capacity to extract 550 tons of material an hour, the company says.


Following that sale last month, Rahco reached its agreement with NexGen, which now is the exclusive supplier of the Spokane companys high-wall mining system, and will help design and market extensions of the basic system.


Rahco builds highly-specialized mining, canal-building, and environmental-remediation equipment for use worldwide. The North Spokane companys annual sales vary greatly but generally range between $30 million and $40 million.