Generally speaking, you'll need a premium vinylester resin with a resin rich corrosion liner.  Depending on temperature, concentration, etc...you may need some additional processing (i.e. steam cure).  Check out these sites for more info:

www.fibercast.com
www.ameron.com

A premium grade vinyl ester with a level 2 corrosion barrier will give you good service life, you may want to look at a dual-laminate construction for longer service life, this is where a fluoropolymer or therme-plastic sheet material is overwrapped with a a Reinforced Thermoset Plastic (RTP), also can't stress that you need the fabrication done by a high quality fabricator, suggest using an accredited ASME RTP-1 fabricator.

http://www.viatec.com

I suggest you take a look at AWWA C-950 to observe the
different:

a)  Types
b)  Grades
c)  Liners

of RTRP.  In addition, epoxy resin is superior.  I recently witnessed mechanical testing conducted on GRE pipes as per
ASTM D-638, 1599 & 2412.  I accepted old MTC for ASTM D-2925; since elastic modulus can readily be interpolated and is based on the resin characteristics.

I would strongly recommend AWWA C-950 to the basis of design and inspection.  

Cheers

Definately use vinyl ester resins.  Dow Chemical and Bayer (just to name a few) have been using fiberglass made with these resins for over 30 years - specifically in their chlor-alkali processes.  I will echo the comments about using an RPT-1 fabricator.  Dow Chemical and Bayer primarily only use ASME accredited fabricators to insure quality, service life, etc.

Much fiberglas equipment that Dow Chemical and Bayer have are lined with PVC and in some cases PVDF depending on the service environment.  This type of dual-laminate construction, as already stated, provides even longer service life of 15-30 years depending on conditions.

I would stick with DERAKANE or HETRON vinyl ester resins.
www.derakane.com
www.hetron.com

If you want more information - let me know.

Greg

We would like to know a manufacturer of small chloralkali plant.