Sulphur is sublimated from solid to gas and then resublimated to purify the sulphur. There is no liquid phase occurs in between the process. Sublimation happens on a pressure of temperature between 25 0C and 50 0C with additional elements such as ammonium chloride, naphthalene, dry ice, iodine, camphor etc. This type of sulphur are most effective in controlling the certain plant diseases.
sulphur is a common feedstock in different chemical production like oil and gas production, fertilizer, sulphuric acid, polymer production, rubber additives, tire additives etc. There are more fields and industries where molten sulphur has wide presence. Most often it is transported in solid or liquid form. The transportation of liquid sulphur requires high safety from contamination and environmental impact.
Liquid sulphur is transported in containers of insulated steel which can have capacity of 3800 USGal. The main thing needed to be handled, its temperature, which should be approx 140°C to avoid the solidification of sulphur. Usually in short distance transportation, low thermal conductivity of sulphur helps in retaining the heat. But in long distance transport, a heating system is required.
For transporting the higher quantity of molten suflur, B-train arrangement is used.
Tank used to carry molten sulphur can't be used to carry something else in the returning time as they can't be cleaned so easily. Which is why such tanks are generally dedicated to hauling sulphur. Although, a special kind of trailer is used in western Canada and Florida region, which has two tanks combined, one for molten sulphur and the other for bulk commodity. This trailer is called as backhoul double. Such trailers are used to maximize the "loaded miles" and to improve the trucking economics. They are used by fertilizer manufacturers and fuel plants.
For long distance oversea transport, ships equipped with heating systems are used to maintain the heat of molten sulphur.