The Linz-Donawitz (LD) process, also known as the basic oxygen steelmaking process, is a method of refining molten pig iron into high-quality steel by blowing pure oxygen into a basic refractory furnace. This process oxidizes impurities like carbon, silicon, phosphorus, and manganese, creating a by-product called LD slag. 

Tata Steel Limited, Jamshedpur has developed a patented technology for producing a first of its kind soil conditioner from the LD slag fines which contains all the essential nutrients required for soil health and plant growth, including calcium, sulfur, iron, silicon, phosphorus, and magnesium. 

LD Slag is one of the most significant by-products of integrated steel plants around the world, particularly from the perspective of government agencies, regulatory bodies and local authorities. India generates more solid waste per ton of steel (approximately 1.2 tons) compared to Western countries (around 0.55 tons). Among this waste, LD slag contributes substantially, accounting for 120 to 180 kg per ton of steel produced. 

Current LD steelmaking processes generate slag with chromium concentrations that exceed acceptable thresholds for reuse, creating a pressing need for scalable solutions that enable this by-product transformation into valuable agricultural inputs. 

The typical chemical analysis of LD slag is as shown in the table below.