Acid Proof Lining and Acid Resistant Lining Work

Acid proof lining protects concrete and steel structures that hold, carry or are splashed by acids, alkalis and solvents. A tank, pit or vessel built from ordinary concrete or mild steel is attacked within months once it goes into chemical service. A properly designed lining puts a barrier of chemical resistant material between the process and the structure, so the structure keeps its strength and the plant keeps running. Kothari Corrosion Controllers has carried out acid proof lining work since 1969 from our works at Odhav, Ahmedabad. We manufacture the acid proof bricks, acid proof tiles and acid resisting mortars used in the lining, and our own trained applicators install them at site. One supplier is responsible for the materials, the workmanship and the finished lining. This page explains the types of lining we carry out, how an acid resistant lining is built, how the mortar is chosen and what we need from you to quote. For process floors, see acid proof flooring.

• ACID PROOF BRICK LINING in 38 mm and 75 mm acid resistant bricks for reaction vessels, acid storage tanks, pickling tanks, absorption towers, neutralising pits and chimney flues. More on acid proof brick lining.
• ACID PROOF TILE LINING in 10 mm to 30 mm tiles for drains, gutters, trenches, dyke walls, sumps and lighter duty tanks. More on acid proof tile lining.
• ACID RESISTANT VESSEL LINING for MS and RCC reaction vessels, MSRL vessels and Nutsche filters, using radial and wedge bricks that follow the curve of the shell.
• ETP AND ZLD TANK LINING with acid and alkali resistant tiles and bricks for equalisation tanks, neutralisation tanks, collection pits and sludge sumps.
• CHIMNEY AND FLUE LINING in acid proof bricks laid in potassium silicate mortar for flue gas ducts, scrubbers and RCC chimneys, for service up to 900 C.
• CARBON BRICK LINING laid in carbon filled mortar for hydrofluoric acid, fluoride salts and strong hot alkalis, where standard acid proof bricks are not suitable.
• MEMBRANE AND COATING LINING with bitumen mastic, epoxy and coal tar epoxy, either as the impervious layer under brick and tile or as a lining on its own for milder duty. See our speciality jobs.

A lining is a system of layers, and it is only as good as its weakest one. In most failed linings we are called to repair, the brick itself is still sound. The failure started at a joint or in the layer underneath.

1. Surface preparation. Concrete is cured, dried and roughened, and steel is grit blasted. Oil, laitance and moisture are removed so that the next layer bonds.
2. Primer. A primer matched to the membrane seals the substrate and gives it a key.
3. Impervious membrane. Bitumen mastic, epoxy or another membrane is applied as the second line of defence. It stops anything that works through a joint from reaching the concrete or steel.
4. Brick or tile lining. Acid proof bricks or tiles are fully buttered and bedded in acid resisting mortar in staggered bond, with joints kept between 2 mm and 6 mm. Walls, floors, kerbs and coves are tied together so that acid has no straight path through the lining.
5. Joint filling and curing. Joints are filled or pointed with the resin mortar and the lining is cured for the time the mortar system needs. Silicate linings are given an acid wash. The lining is inspected before the plant goes back into service.

In heavy duty tanks, two courses of brick are often laid with staggered joints, so that a joint in one course is covered by a brick in the next.

The brick or tile resists the chemical. The mortar sets the limits of the finished lining. We choose the mortar from the chemical, its concentration and the operating temperature, and then the brick thickness from the mechanical load and thermal shock.

Silicate mortars are not used where alkalis are present. For general lining duty, 38 mm bricks or tiles are used. For vessels, pickling tanks and heavy mechanical load, 75 mm bricks are used. Full technical details of each system are on our acid proof mortar and cement page.

Reaction vessels and storage tanks. For vessel lining, bricks are cut or supplied as wedges to follow the curve of the shell, and the lining is designed so that expansion of the steel does not open the joints. On steel shells the membrane is applied after grit blasting. Our crews also reline operating vessels and pickling tanks to a fixed shutdown programme. ETP and neutralisation tanks. Effluent swings between acidic and alkaline, sometimes within hours. Alkali resistant tiles and bricks laid in furane or epoxy mortar handle both conditions, where a silicate mortar would fail. Typical scope covers equalisation tanks, neutralisation pits, collection sumps, ZLD tanks and effluent drains. Pickling, plating and anodising tanks. Steel pickling lines with hydrochloric or hot sulphuric acid, and plating and anodising baths, need 75 mm brick lining on a membrane, with careful detailing at inlets, outlets and the tank top where most leaks begin.

• MATERIALS AND WORK FROM ONE SOURCE. Bricks, tiles and mortars are made in our own works at Odhav, so there is no gap between the material supplier and the applicator.
• IN-HOUSE APPLICATORS. Lining work is carried out by our own trained crews at plants across India.
• SUPPLY ONLY OR TURNKEY. We supply materials with application guidance, or take full turnkey responsibility from surface preparation to the cured lining.
• EXPORT. Lining materials are exported to African countries, the Middle East and across the Asian subcontinent.

To get a quote, send the drawing or tank dimensions, the chemicals and their concentration, the operating temperature, and whether you need supply only or turnkey work. Call +91 9825006626 or +91 9327005777, or email info@acidproof.com.