For the past few years, the 4 Applied Late-Model Patents and 1 Invention Patent in The Active Limekiln Field were awarded, meanwhile, firstly originated an annular double-shaft lime kiln, which is the world's first double-shaft kiln technology that can produce active lime with pure blast furnace gas with less than 750kCal of heat value per normal cubic meter.

1. Advanced design principles: A Parallel-flow heat-accumulation calcining mechanism;
2. Heat Energy Consumption: < 860Kcal/kg quicklime(Low heat value)
3. Fuel: A wide variety of fuel, such as blast furnace gas, coke oven gas, generator gas, converter gas, mixture gas, petro-coke powder coal powder, wood dust, heavy oil etc, can be used.

4. High-quality lime products: Lime activity ≥ 350ml, up to 440ml (4NHCl, 5min titration), Light burning & over burning rate ≤ 5%.
5. An advanced annular design, A unique channel design, An optimized design of refractory materials narrows the range of applicable refractory bricks of the annual double-hearth kiln to just 6 types and thus greatly reduces the complexity of brick types.