In 2010, nearly 20% of China's current cement production was from relatively obsolete vertical shaft kiln
(VSK) cement plants, with the remainder from modern rotary kiln cement plants, including plants equipped with new suspension pre-heater and pre-calciner (NSP) kilns.
It wasn't until some 20 or 30 years later that a new type of kiln -- the shaft kiln
-- was developed.
It is especially worrisome when we found out that smaller and medium-sized cement producers in Vietnam use old technology such as shaft kilns
in producing cement and sell such products to pure importers in the Philippines at prices below the cost of production of domestic cement manufacturers."
" He mentions the continued use of shaft kilns
by some small- and medium-sized cement manufacturers in Vietnam.
The Alekseevka lime factory has two shaft kilns
and a grinding plant, and total annual production capacity of some 70,000 tons of quicklime.
The company plans construction of two new rotary lime kilns, which will replace the shaft kilns
built in 1924.