molten sulphur filter

Molten Sulphur Filter


Molten Sulphur Filter


Sulphur is a significant component of many industrial processes and is one of the world’s most important resources. Sulphur is burned at high temperature and leaves a residue called sulphur Di-oxide during generating Sulphuric Acid from elemental sulphur through the acid manufacture method as well as Chamber & contact. Because the presence of solid debris or ash in the acid plant can cause serious problems, molter sulpheric filters are used in this operation. The primary goal of employing these is to remove any particles that could cause problems in suplhur manufacturing.Impurities such as ash, dust, organic particles, and carbon particles, such as asphaltides and bitumen, must be removed from molten sulphur applications using appropriate filtration techniques.

These contaminants might have a significant impact on the subsequent process if not filtered properly, causing major operational disruptions. Choosing the right equipment for your molten sulphur filtration process is critical to ensuring that your sulphur plant runs smoothly, safely, and efficiently.

Sulphuric acid-derived molten sulphur has a high freezing point and an unusual viscosity, making it challenging to handle. When the temperature of molten sulphur is raised from its melting point (110) to 157oC, the viscosity of the liquid sulphur drops dramatically, then rises again as the temperature rises. All valves, lines, and filtration equipment are steam jacketed to maintain a constant temperature of molten sulphur during the filtration process.

A typical molten sulphur filter system consists of two stages of filtration. A horizontal pressure leaf filter is followed by a polishing/safety cartridge filter in this arrangement.

Horizontal pressure leaf filter is in two types for molten sulphur filtration:-

  • Shell retraction design – In shell Retraction design leaf remains steady and shell is retracted to & fro.
  • Bundle retraction design – In bundle Retraction Design shell is steady and leaf bundle is retracted to and fro.

Both the versions are operated (for opening and closing of filter) hydraulically for ease of operation. Filtration area : from 5 m2 to 200 m2.


The filter is first precoated with filter aid (kieselguhr or perlite). Molten sulphur from sulphur pits is delivered to the filter for ash filtration after precoating. Steam is used to dreid the filtering cake. After the filter has dried completely, the cake is manually removed by knocking at the leaf bottom with a wooden spatula.

Typical Filtration Cycle


Filter vessels are typically made of carbon steel or boiler-quality material and are jacketed. Filter leaves are constructed of stainless steel and have a five-layer construction. The leaves are riveted or fastened together.

Cartridge Filter for Sulphur Polishing

After the main molten sulphur filters, a cartridge type polishing filter is added to remove traces of fine suspended ash and filer aids that escaped from the main filter and could clog the plant’s downstream equipment. The removal of these tiny materials will aid in the smooth operation of downstream equipment without interruptions. As a result, the plant’s downtime will be significantly reduced.

Features & Benefits

  • High sulphur filtrate quality removing up to a maximum of 10 ppm of solid impurities
  • Reduction of contamination reduces the acidity of the sulphur and reduces corrosion
  • Easy to install: minimum installation required
  • Cost effective: limited onsite installation costs
  • Easy to connect
  • Civil works are minimized


  • Pharmaceutical industry
  • Beverage industry
  • Biodiesel industry
  • Varnish industry
  • Resin industry
  • Lacquer industry
  • Edible oil industry

Product Enquiry