Dastgir,

 Based on this information:

 http://www.business-standard.com/india/news/sulfuric-acid-may-trade-close-to-zero/355822/

there could be a temporary opportunity for cheap sulfuric acid.
However, before the drop in price, the typical cost was 450$/ton(H2SO4).
Since 0.57 tons of H2SO4 are needed to produce 1 ton of gypsum, this would imply a cost of 250 $/ton(gypsum) only for the purchase of sulfuric acid.
I wonder what would be the processing cost!

How much is the cost of gypsum today?
I just checked: something between 15$/ton(gypsum) to 50$/ton depending on the quality.

Looks like it is not economical, unless some cheap stream is available, low grade or waste.

Michel

It could be by product from power plant (or other processes), we call chemical gypsum or artifical gypsum.

 It cause very very long setting of cement. If we mix 50:50 with natural gypsum, setting time is longer  than 3 time compare to natural one.

FYI

Tam

Dear All,

It is nothing that sort. It is being produced by reaction between CaCO3 and H2SO4 which

yield CaSO4.

Moreover Shree Cement is producing it commercially, but they are not revealing any thing it. We have also prepared this in our lab and after proper washing, nothing harmful has happened to cement quality. The most baffling point here is cost effectiveness. How they doing that. Have they devised anything out of box. God knows.

Regards,

Gulam Dastgir