Production Capacity

A Third generation VSBK can produce 4000 Afghan standard bricks (220 x 105 x 68mm) per shaft per day. To replace a standard BTK with a VSBK, four shafts are required. It can be operated 360 days a year and produce 5.5 million bricks, compared to 4.5 million bricks with a BTK.

Coal Consumption

VSBK is the most energy efficient brick-making technology available currently. VSBKs in Afghanistan consume 50% less coal than BTKs. The saving in coal contributes significantly in reduction of operation cost in any brick kilns. Since VSBK can use coal of lower quality than a BTK (lower calorific value) the coal cost per brick can be even lower than 50%. However, absolute consumption figures vary from kiln to kiln, since each soil requires a specific amount of process energy, depending on its chemical properties and external climate conditions.

Brick Quality

A well operated VSBK produces a similar or even higher brick quality (compressive strength) than a BTK. Tests of the VSBK bricks produced in Kabul showed compressive strength of 250 kg/cm². In addition, VSBK produce bricks of homogeneous quality with breakage rate of around 5-10%. However, to produce bricks with similar colour and ring properties as in BTKs, fine tuning (right clay selection, proper ageing, pugging and drying) of the green brick making method and firing is required.

Production Costs

VSBK reduces the coal cost compare to BTK considerably. For the equivalent brick production, the energy cost is reduced by 50% in VSBK compared to BTK. But operating a VSBK requires a relatively bigger and more disciplined firing crew than a BTK. The exact staff number depends on the brickyard’s level of mechanisation and the entrepreneurs’ staff management. A few additional workers are needed for additional tasks such as coal crushing and mixing with clay and operating the pug mill, but unlike in a BTK, special kiln loaders and un-loaders are not required in VSBK. Because of economies of scale, the more shafts a facility has, the less the production costs will be. The production cost per brick of a four-shaft VSBK in Afghanistan would be at least 15% less than a two-shaft VSBK.

Economic Performance

Experiences in other South Asian countries show, that after the supply and operation are optimised, a VSBK of four or more shafts can compete economically with a BTK. Since a VSBK requires a higher capital investment than a BTK, the pay back period for the VSBK is generally longer than compared to a BTK. However, because of the substantial saving in energy costs, operating a VSBK is more economical than a BTK. Experience in Afghanistan shows that an entrepreneur with a four-shaft VSBK can save up to 2.5 million Afghanis annually in energy costs alone.