In Vietnam, field clay is used as material for producing baked bricks and tiles. Statistics show that in order to produce about a thousand tiles, approximately 2 cubic meters of material clay are needed. Thus, in order to meet the demand for bricks and tiles in construction, thousands of hectares of arable soil are used. In the long run, this situation will affect agriculture and the environment in a negative way. With a continuous increase of 10 to 12% per year in the demand for building material, if we only use field clay in tile production, by 2020 about 60 to 64 million cubic meters of clay will have been consumed, i.e. roughly 3.2 thousand hectares of arable land will no longer be cultivated.

In addition, using the traditional technology of burning bricks, the productivity is not high. Meanwhile a considerable amount of various toxic emissions such as sulfur dioxide, carbon dioxide, dust and solid waste is released into the atmosphere, negatively affecting human’s health and the environment.

To improve such a situation, a new technology for producing bricks and tiles has been introduced to and applied in Vietnam by Thach Ban Joint Stock Company. This technology has been used in countries with advanced tile production technology such as Germany, Spain, Italy and China, known as the “semi plastic technology”.

In countries with developed technology in bricks and tiles production, the semi plastic technology has been used for a quite long time and brought about many benefits. The most noticeable is that it does not use field clay as material but use only the types of soil unsuitable for agriculture, such as different types of hill soil, discarded surface soil in the mine exploitation, coal cover, acid coal, furnace slag, brick waste, demolition products including wall construction, roofing tiles. Even discarded roofing tiles and furnace slag could be ground and recycled at the factory so they can be reused as material for building.

In production of bricks with semi plastic technology, a specialized machine system is used to process the raw materials, mixing them together into a specific blend used for each particular type of product such as building bricks, roofing tiles or floor tiles. After that, the mixture is shaped and transferred to the kilns for burning.

In particular, the process of brick production will take place in a specially designed system, under low moisture condition so that no drying process either in green house system or on drying yard is needed. Instead the bricks will be taken directly into kilns. Therefore, compress and bending intensity and plaster sticking ability of bricks will be 2 to 3 times higher, the final bricks will be significantly improved in quality and shape.

For baked brick-oven drying systems, furnaces are specifically designed to suit each different product category, in order to make the most efficient use of energy. Besides, this technology would reduce the use of greenhouse drying area and is much less dependent on the weather, helping to save time and energy. Also, compared with old technology, by eliminating the drying process and minimizing manual arrangement of bricks, this technology helps reduce labor cost by 30 - 35%. Especially by reusing production waste as raw materials, the technology also minimizes the amount of scrap after production.

Furthermore, with many advantages it brings, the new technology does not increase the production costs. Therefore the market price of brick and tile products using semi flexible technology is only equal to the price of similar products using traditional technology. With these advantages, it is considered to be one of the brick and tile production technology that will be widely applied in the near future. 

By Nguyen An