Granite Tanks
Granite Tank — Granite Pickling Tank for Hot Dip Galvanizing
The granite tank is used in the chemical pretreatment stage of the hot dip galvanizing process — typically for pickling and degreasing — where steel parts are treated with acid or alkaline solutions before entering the zinc kettle. Granite is a naturally acid- and alkali-resistant stone, making it a durable alternative to PP or stainless steel for tanks that hold corrosive pretreatment solutions.
Annuo’s granite tanks are built with a steel structural shell lined internally with an acid-resistant barrier layer, over which flat granite slabs are installed to form the acid-contact surface. This construction combines the structural strength of steel with the natural chemical inertness of granite, keeping the corrosive solution fully isolated from the metal structure.
Construction & Advantages
Steel shell + granite slab lining: a steel structural frame provides rigidity and load-bearing strength, while flat granite slabs line the interior surface in contact with the acid or alkaline solution
Natural acid and alkali resistance: granite is chemically inert to most acids and alkalis used in HDG pretreatment, including hydrochloric acid solutions used for pickling
Crash and impact resistant: the dense, rigid stone surface resists mechanical damage better than thinner plastic linings, making it well-suited to environments with heavy parts handling
Flexible installation, simple maintenance: tanks can be configured to fit different plant layouts, and the smooth, non-porous granite surface is straightforward to clean and inspect
Long-term stability: because granite does not corrode chemically the way metal does, the tank lining maintains its structural integrity over many years of acid exposure
Granite vs PP vs Stainless Steel Pretreatment Tanks
Material
Acid resistance
Impact resistance
Notes
Granite
Excellent — naturally inert
High — dense, rigid stone surface
Well-suited to heavy parts handling and high-impact environments
Excellent — chemically inert
Moderate
Lighter weight, easier to fabricate into custom shapes, easy leak repair
Stainless Steel
Poor in chloride/HCl environments
High
Prone to pitting corrosion in HCl; typically 1 – 4 years service life
Granite tanks are a strong choice where mechanical durability and long-term chemical stability are priorities. If your line needs lighter, more easily customized tank geometry, see our PP Pickling Tank page for comparison.
