Abstract This invention relates to a process for preparing magnesium chloride pellets suitable for fusion electrolysis to produce magnesium metal. Solid particles of magnesium chloride hydrate, such as the dihydrate, are agglomerated with molten magnesium chloride hydrate, such as the tetrahydrate, to form a raw pellet product having a moderate moisture content, such as about 2.8 moles of H2O per mole of MgCl2. The raw pellets are further dehydrated in a shaft kiln to the extent desired. It is possible to prepare a raw-pellet product that can be dehydrated to substantially anhydrous magnesium chloride in a one-stage dehydration operation. The solid particles of magnesium chloride hydrate advantageously are prills, suitably of a size between 0.2 and 1.0 mm.
A process according to claim 1 wherein the agglomerates formed in step b) which have a degree of hydration in the range of 2.5 to 3.5 moles of water per mole of magnesium chloride are air dried until they have a degree of hydration of between 2 and 2.5 moles of water per mole of magnesium chloride.
Claim 2
Dependent Claim
20 words
A process according to claim 1, wherein the agglomerates are prepared in a size range between 8 and 12 mm.
Claim 3
Dependent Claim
27 words
A process according to claim 1, wherein the agglomerates are dehydrated in step c) and step d) by using HCl as the drying gas in each step.
Claim 4
Dependent Claim
25 words
A process according to claim 4, wherein said heated liquid magnesium chloride hydrate has between 3.9 and 4.3 moles of water per mole magnesium chloride.
Claim 5
Dependent Claim
64 words
A process according to claim 1, wherein said heated solid magnesium chloride hydrate having 2 moles of water per mole magnesium chloride and a temperature of about 150*C and said liquid magnesium chloride hydrate having 4 moles of water per mole of magnesium chloride and a temperature of about 190*C are fed to said agglomerating means to form agglomerates having a temperature of 160*C.
Claim 6
Dependent Claim
14 words
A process according to claim 1, wherein said agglomerating means is a pelletization disk.
Claim 7
Dependent Claim
23 words
A process according to claim 1, wherein said heated solid particles are prills having a size range of about 0.2 - 1 mm.
Claim 8
Dependent Claim
18 words
A process according to claim 1, wherein spray dried magnesium chloride hydrate is used as said solid particles.