Natural resources are consumed 50% faster than they can be replaced. The term circular economy has become the ultimate goal of all big corporation in recent years. Under the circular economy concept, resources are redeployed and reused, and waste flows are turned into inputs for further production. Truly embedded with that ambition, INSEE continuously researches and challenges conventional thinking to implement the circular economy concept in all our manufacturing process.
Clinker is one of the main components that cannot be totally replaced in cement composition. Clinker is condensed from natural resources which requires the e orts and collaboration of many teams and functions. As a result, we never use it waste-fully. At INSEE, we understand that every tone of clinker saved could lead to many benefits, not only saving costs for our business but also for the environment. For many years, the clinker factor (CF) has been controlled closely. Every cement solution, which we deliver to end users, is optimized to ensure it is t for purpose and suitable for its dedicated application.
By using fly ash and steel slag to substitute clinker in cement production, INSEE in Vietnam has significantly controlled its clinker factor. This reduction in CF has been carried out without compromising either industrial performance or product quality but even improving it.
In addition, the use of high- quality mineral components (MIC), such as pozzolana, or prepared industrial waste, results in more efficient usage of non-renewable raw materials (limestone) and a lowering of CO emissions by at least 24% per tone of cement produced while increasing some aspect of quality such as durability and anticorrosion.
State-of-the-art new suspension process (NSP) kilns include multi-stage pre-heaters and pre-calciners to pre-process raw materials before they enter the kiln, and an air-quench system to cool the clinker product. Kiln exhaust streams, from the clinker cooler and the kiln pre-heater system contain useful thermal energy that can be converted into power. Typically, the clinker coolers release large amounts of heated air at 250 to 340°C directly into the atmosphere. At the kiln charging side, the 300 to 400°C kiln gas coming o the pre-heaters is used to dry material in the raw mill and/or the coal mill and then sent to bag filter houses to remove dust before finally being vented to the atmosphere.
If the raw mill is down, the exhaust gas would be cooled with a water spray or cold air before it entered the dust collectors. Maximizing overall kiln process efficiency is paramount for efficient plant operation while remaining waste heat from the pre-heater exhausts and clinker coolers can be recovered and used to generate power to o set a portion of power purchased from the grid.
It offers enormous benefits for the economy, society and environment, meeting 25% of the plant’s electricity demands, equivalent to electricity for 18,000 households in one year, relieving pressure on the national grid supply and generating around 6MW of power, this system enables INSEE Vietnam to indirectly eliminate approximately 25,000 tons of CO per year, equivalent to 9,300 tons of coal/year.