Sulphur-clay prills
AssigneeCanadian Superior Oil Ltd.
InventorsBarney D. Garrison, Jr., Barry S. Marjanovich
Life of this patent
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Abstract
Substantially spherical, water-degradable, sulphur clay particles or prills are provided; the particles are formed by passing a mixture of molten sulphur and a particulate swelling clay through a plurality of orifices and into an aqueous solution of a water soluble electrolyte salt, maintained at a temperature effective to cool the mixture below its solidification temperature. An improved apparatus is also provided in which a high constant static head of molten material is let down to a low static head whereby molten material at low velocity falls under gravity into the aqueous electrolyte salt solution.
Claims26
A process for producing substantially spherical, water degradable, sulphur-clay particles comprising:
- passing at least one stream of a mixture comprising molten sulphur and a particulate swelling clay into an aqueous solution of a water soluble electrolyte salt, said solution comprising about 5 to 15%, by weight, of said salt and about 85 to 95%, by weight, of water,
- maintaining said solution at a temperature effective to cool said mixture below its solidification temperature,
- allowing the surface tension of the molten sulphur to break up said stream in said solution to form substantially spherical droplets and allowing said droplets to cool and solidify in said solution to form said substantially spherical particles,
- withdrawing said particles from said solution and drying said particles.
A process for producing water-degradable, sulphur-clay prills comprising:
- forming a high static head of a mixture comprising molten sulphur and a particulate swelling clay,
- allowing said mixture to fall through a plurality of orifices to form a low static head of the mixture,
- feeding the mixture in the low static head in a plurality of continuous streams of circular cross-section into an aqueous solution of a water soluble electrolyte salt, said solution comprising about 5 to 15%, by weight, of said salt and about 85 to 95%, by weight, of water and being maintained at a temperature effective to cool said mixture below its solidification temperature,
- allowing the surface tension of the molten sulphur to break up said streams in said solution to form substantially spherical droplets and allowing said droplets to cool and solidify in said solution to form said prills,
- withdrawing the prills from said solution and drying said prills, said swelling clay being present in said mixture in an amount to provide a content of clay in said prills effective to render the prills water degradable.
In a method of forming solid, substantially spherical particles from a molten, solidifiable material, comprising feeding the molten material in a plurality of continuous streams into a forming medium effective to cool said molten material below its solidification temperature to form solid, substantially spherical particles, the improvement wherein said molten material is allowed to fall from a constant high static head through a first plurality of orifices to form a constant low static head of said molten material above said forming medium, said low static head being vertically below said high static head, and allowing said molten material to fall through a second plurality of orifices from said constant low static head in said plurality of continuous streams into said forming medium, said high static head having a depth of 40 to 50 times the depth of the low static head.
A process for producing water-degradable, sulphur-clay prills comprising:
- forming a high static head of a mixture comprising molten sulphur and a particulate swelling clay, said swelling clay being present in said mixture in an amount effective to produce sulphur-clay prills containing about 7 to 12%, by weight, of said swelling clay,
- allowing said mixture to fall from said high static head through a first plurality of orifices to a distribution means in which an intermediate static head is formed, said intermediate static head being vertically below said high static head,
- allowing said mixture to fall from said distribution means through a second plurality of orifices to form a low static head of the mixture at a temperature of about 250.degree. F. to about 270.degree. F., said low static head having a depth of not more than about 0.5 inches, and said high static head having a depth of 40 to 50 times the depth of the low static head,
- and said low static head being of lower depth than said intermediate static head, said low static head being vertically below said intermediate static head,
- allowing the mixture in the low static head to fall from the low static head through a third plurality of orifices in a plurality of continuous streams of circular cross-section into an aqueous solution of a water soluble, inorganic electrolyte salt, said solution having an upper surface spaced 2 to 6 inches below said low static head, and consisting essentially of about 5 to 15%, by weight, of said salt and about 85 to 95%, by weight, of water, said solution being maintained in a quiescent state at a temperature of about 140.degree. F. to about 170.degree. F.,
- allowing the surface tension of the molten sulphur to break up said streams in said solution to form substantially spherical droplets, and allowing said droplets to cool and solidify in said solution to form prills,
- withdrawing the prills from said solution, drying said prills and
- recovering said prills as sulphur-clay prills having a smooth, hard, substantially spherical surface, and containing 88 to 93%, elemental sulphur and 7 to 12% swelling clay, in weight percent, with an internal moisture content, in weight percent of 0.02 to 0.17 and a surface moisture content of 0 to 1.5%,
- the orifices of said first plurality having a diameter greater than the orifices of said third plurality, the third plurality being greater than the first plurality such that the total cross sectional area of orifices in the third plurality is greater than in the first plurality,
- said orifices of said second plurality having a cross-sectional area smaller than the orifices of said first plurality and greater than the orifices of said third plurality, the total cross-sectional area of the orifices of said second plurality being greater than that of said first plurality and less than that of said third plurality,
- said orifices of said third plurality having a diameter of 1/16 to 3/32 inches and being spaced at least 3/4 inches apart.
Dependencies are inferred from the claim text.