Improvements in or relating to the Production of Boracic Acid and other Products.
Year: 1899

page_text: Date of Application, 11th Oct., 1899
Complete Specification Left, 15th Mar., 1900-Accepted, 26th May, 1900
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Production of Boracic Acid
and other Products.
I, CHARLES CLIFTON MOORE, of 11, Old Hall Street, Liverpool, in the County of
Lancaster, Chemical Engineer, do hereby declare the nature of this invention to be
as follows:
The object of this invention is to effect the complete decomposition of crude
commercial borates in such a manner as to avoid the loss of boracic acid which occurs
in the manufacture of borax as carried out at present, and at the same time to obtain
other products of commercial value.
The crude borate of lime or magnesia, or other crude borate, in a fine powder is
suspended in water (or mother liquor from a previous operation) and chlorine gas is
passed into the mixture which is kept agitated. During the treatment with chlorine
the mixture may be maintained at a temperature of 60-80 degrees Centigrade with
advantage, but this is not essential. The absorption of the chlorine, which may be
very rapid, when completed results in the whole of the combined boracic acid
(contained in the crude borate) being set free while the bases contained in the crude
borate from chlorides and chlorates equivalent to the chlorine absorbed. The liquor
obtained in this manner, after settling out any insoluble residue, is cooled and most
of the free boracic acid crystallised out. The mother liquor from the crystallisation
may be used to mix with a fresh quantity of crude borate and again treated with
chlorine as described. Or the mother liquor may be concentrated by evaporation and
after separation of the boracic acid by cooling the residual liquor may be treated to
extract the chlorates contained in it by the usual means.
The boracic acid prepared in the manner described is easily made perfectly pure
by re-crystallisation, and if it is desired to prepare borax is simply treated with
solution of caustic soda or carbonate of soda. The method described is meant to be
worked in conjunction with the production of chlorine and soda by electrolysis so that
both products can be utilised as they come from the cell.
When a crude borate of lime is treated in the manner described the chemical
reactions may be represented as follows:-
3 (Ca2, B4, 08, 3 H20) × 6 Cl2 x 9 H20
=
12 H3 B03 x 5 Ca C12 x Ca (ClO3)2.
The solution obtained contains boracic acid, calcium chloride and calcium chlorate.
If a borate of magresia is substituted for that of lime, then chloride and chlorate of
magnesium would obviously be contained in the solution with the boracic acid, and so
on depending upon the bases contained in the crude material.
The greater the concentration of the solution containing the chloride and chlorate,
the more completely will the boracic acid crystallise from the same. Or the boracic
acid may be removed from the solution by cooling the same to a very low temperature.
After the separation of the boracic acid in the manner described, the residual solution
containing the chloride and chlorate is treated for the extraction of the chlorate in
the usual way.
10:1 1
1000

page_text: Improvements in or relating to the Production of Boracic Acid
and other Products.
I, CHARLES CLIFTON MOORE, of 11, Old Hall Street, Liverpool, in the County of
Lancaster, Chemical Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The object of this invention is to effect the complete decomposition of crude
commercial borates in such a manner as to avoid the loss of horacic acid which
occurs in the manufacture of borax as carried out at present, and at the same time
to obtain other products of commercial value.
The crude borate of lime or of magnesia or other crude borate in a fine state of
powder is suspended in water or mother liquor from a previous operation, preferably
in about the proportion of 2-3 lbs. borate to the gallon of water and chlorine gas
is passed into the mixture which is kept agitated. During the treatment with
chlorine, the mixture is preferably maintained at a temperature of from 60 to
80 degrees Centigrade. The absorption of the chlorine, which in such case is very
rapid, results on completion in the whole of the combined boracic acid contained
in the crude borate being set free, while the bases contained in the crude borate form
chlorides and chlorates equivalent to the chlorine absorbed. The liquor obtained in
this manner after settling out any insoluble residue is cooled preferably to about
15-20 degrees Centigrade, and most of the free boracic acid is thereby crystallized
out. The mother liquor from the crystallization may be used to mix with a fresh
quantity of crude borate and again treated with chlorine as desired, or the mother
liquor may be concentrated by evaporation, and after the separation of the crude
boracic acid by cooling, the residual liquor may be treated to extract the chlorate
contained in it by the usual means. Boracic acid prepared in the manner described
is easily made quite pure by recrystallization, and if it be desired to prepare borax
instead of boracic acid, it is simply treated with a solution of caustic soda or carbonate
of soda (either in the form of soda ash or in the form of crude bicarbonate of soda
such as is obtained by the ammonia soda process) in equivalent proportions, according
to the amount of boracic acid present. The method as described may be worked
advantageously in connection with an electrolytic process producing both soda and
chlorine, in which case both products could be utilized as they come from the cell.
When a crude borate of lime is treated in the manner described, the chemical
reactions may be represented as follows:-
3 (Ca,B,O, 3 H,O) + 6 Cl, + 9 HO = 12 HBO, + 5 CaCl2 + Ca (C1,O₂) 2
The solution obtained contains boracic acid calcium chloride and calcium chlorate.
If a borate of magnesia be substituted for that of lime, then chloride and chlorate
of magnesia would obviously be obtained in the solution with the boracic acid, and
so on, depending upon the bases contained in the crude material. The greater the

page_text: the reaction or the separation of the boracic acid. Any organic matter is destroyed
by the chlorine, while the sulphate is converted into sulphate of lime (provided that
calcium salts are present) which is practically insoluble in the hot solution of calcium
or magnesium chloride and chlorate. Any chloride contained in the crude borate
would obviously remain dissolved in the mother liquor. In this respect the
method is not in the least affected in dealing with very impure crude borates which
offer such great difficulties when dealt with by the present process of manufacture.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The method or process of producing boracic acid from crude borates, which
consists in suspending the finely divided crude borate in water or an aqueous
solution, passing chlorine into the mixture and separating the boracic acid and
afterwards the chlorate from the same, substantially as described.
2. The complete cycle of operations whereby the mother liquor of one operation
is used in which to treat the crude borate with chlorine in the following operation
substantially as and for the purposes described.
3. The manufacture of chlorate by the use of crude borate, chlorine and water,
substantially as described.
Dated this 14th day of March 1000
WM. P. THOMPSON & Co.
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.