Interconnected system and method for the purification and recovery of potash

The present invention provides a kiln for the combustion of agricultural waste. The kiln includes a central cylindrical combustion chamber. The central cylindrical combustion chamber includes a system for the control of combustion air to the combustion chamber. The kiln includes a second concentric cylinder surrounding the central cylindrical combustion chamber. The second concentric cylinder includes a system for the flow of cooling water through the first annulus between the central cylindrical combustion chamber and the second concentric cylinder. The kiln includes a system for the feeding of the agricultural waste into the central combustion chamber. The kiln includes a temperature sensing device to measure and display the temperature within the central combustion chamber during the combustion of the agricultural waste. The kiln includes a system for the recovery of ash from the kiln. In operation, the temperature of combustion is controlled to between 550° C. and 650° C. by a combination of increasing the supply of combustion air when the temperature in the central combustion chamber falls to near 550° C. and the introduction of cooling flowing water when the temperature in the central combustion chamber approaches 600° C.