FR2642744A1 - Process for the chemical modification of mother liquors of marine origin and solutions and products obtained by making use of this process - Google Patents

Abstract

Process for the chemical modification of mother liquors of marine origin, characterised in that, to obtain fertilising solutions which can be diluted by starting with residual mother liquors and before the crystallisation of its potassium chloride, and to obtain crosslinking solution for the manufacture of cements based on alkaline-earth metals starting with mother liquors with a higher concentration of magnesium salts, at least one inorganic salt is introduced, at ambient temperature and merely by mixing into them, which has a dissociation constant pKa ranging up to 4.5 at 25 DEG C, and/or one of the liquid or soluble acidic phosphates, and ammonium hydroxide is then added. The process according to the invention is intended to provide a fertilising solution as well as a reliable chemical cement.

Description

Process for the chemical modification of mother liquors of marine origin as well as the solutions and products obtained by the implementation of this process.

The present invention relates to a method for modifying
chemically mother waters of marine origin, after these
they have deposited most of their chloride
of sodium and before crystallization of potassium chloride
they contained in order to obtain, at low concentration, a dilutable and high concentration fertilizing solution a crosslinking solution for cements based on oxide, hydroxides and alkaline-earth metal carbonate.

We have known for a long time, the use of algae
As a soil amendment, more recently,
seaweed extracts solubilized to treat all plants, we also know the use of lime water recovered
after the extraction of magnesium hydroxide from mother liquors highly concentrated in magnesium salts.

It will be understood that the use of algae # as is, is not particularly practical and is reserved for residents of
the sea, the peaches and solubilized algae are of uni price of
come back high and are therefore not particularly economical, as for the wastewater they do not possess
dent plus many effective mineral and organic elements for crops.

It is also known that, in place of crystallized magnesium sulphates and chlorides, the use for the preparation of magnesium cements, mother liquors highly concentrated in magnesium chloride, but the presence of the other salts as such in these waters, are undesirable and They do not provide satisfactory results for the strength and reliability of the products obtained.

Irrespective of the sea salt sodium chloride - Nazi, the sea water contains all the known mineral elements, more or less quantity. Practically when the seawater-mass voluminal 1026 g / l- is subjected to evaporation, it begins to let precipitate the calcium sulfate it contains, then reaches at 1216 g / l saturation NaCl.For To avoid depositing some of the other salts together with sodium chloride, the brines are removed from saline salt marshes when they reach a concentration close to 1 263 g / l of density.
NaCl, salt or crystalline tables drain brines are then mother liquors which will be, in only a small part, used as raw material for the manufacture of magnesian derivatives, all the rest being rejected to the sea.

The residual mother liquors contain almost all the elements, in various forms, including trace elements and mineral salts, contained in the sea but in a more cencentric way. They also have an organic fauna: helophite seeds, microscopic algae in very large quantities of phyteplancton single-cell, salt marshes are known to be natural micro-biological scrubbers.

The bactericidal power of the marine environment is known to be specific to planktonic diatomaceous substances, the phyto-planktonic density is particularly great on a salt marsh, the result is an antibiotic activity considered as rabis vis-à-vis non-specific bacteria of the sea salt.

It is known to chemically transform a chloride into another salt using the known method of moving a weak acid with a strong acid.

The purpose of the present invention is to chemically modify mother liquors of marine origin so as to obtain, on the one hand, a dilutable solution that can be assimilated by all the plants and, on the other hand, a crosslinking solution for the manufacture of chemical cements. resistant and reliable.

To this end, the invention relates to a process for the chemical modification of mother liquors of marine origin, characterized in that for obtaining a dilutable fertilizing solution from residual mother liquors and before crystallization.
of its potassium chloride, and for obtaining solution
of crosslinking for the preparation of metal-based cements
alkaline earth from mother waters with higher concentrations
In Sslsmagnesian, it is introduced at room temperature.

and by simple mixing in them, at least one acid inor
with a dissociation constant (pKa)
up to 4.5 to 250C and / or one of the liquid acid phosphates or
soluble, and then ammonium hydroxide is added.

According to the present invention, at least one inorganic acid having a dissociation constant (pKa) of up to 4.5 to 25 ° C is used for treating the mother liquor. The value expressed by loglOKa is preferably one of the phosphoric acids of minus 50, orthophospheric or pyrophosphoric.

Another feature of the invention consists, in order to modify the mother liquors, in order to obtain fertilizing solutions, to use, combined or not with an inorganic acid, a soluble acidic pllosphate such as for example. sodium phosphate, potassium phosphate or ammonium phosphate such as mono, di or tripotassium phosphate or mono or diammonium phosphate.

According to another characteristic of the invention, magnesium salts which are intended to obtain crosslinking solutions, whether or not combined with an inorganic acid, a soluble ammonium phosphate or an acidic phosphate, are mixed in the mother liquors which are very concentrated. soluble in water such as acidic zinc orthophosphate, acidic iron orthophosphate, acidic magnesium orthophosphate, acidic aluminum orthephosphate, zinc acid pyrophosphate, etc.

 According to the invention is incorporated after the mixture of at least one inorganic acid and / or an acidic phosphate in the mother liquors to be treated, ammonium hydroxide NIi4OII preferably reduced to 20/22 B.

It will be understood that mother waters of marine origin may come either from salt marshes - saline - or from partially evaporated and usable seawater, according to the invention, once it has decanted the most much of the sodium chloride it contains, without waiting for the crystallization of potassium chloride.

From this solution, after dilution to 1000 times by weight in fresh water, a highly fertilizing solution for foliar or root applications on all plants will be obtained.

By way of example only, the fertilizing solution will be obtained by simply mixing: EXAMPLE 1
Mother waters of marine origin or residual salt marshes D i 245 1000 Phospheric acid 500 = 50% by weight of mother liquor ammonium hydroxide 100 = 10%
1600 to dilute up to 1000 times in fresh water.

After the mother liquors have evaporated further and have deposited a large part of magnesium sulphate mixed with magnesium and potassium chlorides, highly concentrated solutions of magnesium chloride are obtained. These solutions will be used as raw material to obtain, after various treatments, magnesium derivatives: hydroxides, oxides and carbonates.

It is possible to use these concentrated mother liquors after chemical modifications, according to the invention, as a crosslinking solution for producing cements based on alkaline earth metal oxides, hydroxides or carbonates. Magnesium oxides, zinc, titanium dioxide, natural double carbonates such as dolomite, etc.

The preparation of the crosslinking solution for alkaline earth metal cement from the concentrated mother liquors is obtained as follows: EXAMPLE Z

<tb> Concentrated <SEP> mothers <SEP><SEP> D = <SEP> 1 <SEP> 325 <SEP> 1000
<tb> Acid <SEP> Phosphoric <SEP> 500 <SEP> 500 <SEP> = <SEP> solution
<tb><SEP> = <SEP> solution
<tb> hydroxide <SEP><SEP> of am <SEP> oniuTn <SEP><SEP> 100 <SEP> concentrated
<Tb>
The crosslinking solution may be incorporated in 95% concentrated mother liquors or magnesium salt solutions.

EXAMPLE 3

<tb> Concentrated <SEP> mothers <SEP><SEP> D = <SEP> 1 <SEP> 325 <SEP> 1000
<tb> Phosphate <SEP> of <SEP> Zn, <SEP> Al, <SEP><SEP> Fe, <SEP><SEP> 15 <SEP> = <SEP> 1.5% <SEP> of <SEP ><SEP> waters
<tb> Ammonium hydroxide <SEP><SEP> 3 <SEP> = <SEP> 0.3% <SEP> - <SEP> Mothers <SEP>
This crosslinking solution is mixed with fine powders of oxide such as MgO in a proportion of 50 to 100% relative to the said solution. After a very homogeneous mixture, dyes, various fillers such as mineral or organic fibers or vegetable fibers - glass fibers, rock, metal, plastics, such as aramids polyolefins, polyamides, etc. - marine sand, quartz stones and aggregates various, electro-melted metals , carbonate of lime, marble etc .., may be incorporated in the cements obtained according to the invention.

The setting of these cements can be controlled over time, for this it will suffice to incorporate, depending on the temperature and the ambient hygrometry, up to 5% by weight of the sulphate or calcium oxide cement, the sulphate aluminum or Portland cement.

 As can be understood, the formulations can be adapted according to the needs, it will suffice to vary the parameters of the known formulas to obtain extremely reliable products.

According to another embodiment of the invention, it is possible to lighten a mortar or expander a pure cement or in which reinforcing fibers have been added, by incorporating a cell-regulating product such as a colloid, hydrocolloid of propylene glycol mono or diglyceride and the like. similar products.

The expansive agent will preferably be long-termed hydrogen peroxide for these uses.

Claims (7)

R E V E N D I C A T IO N S 1.- Process for the chemical modification of mother liquors of marine origin, characterized in that at least one inorganic acid having a dissociation constant (pKa) of up to at 4.5 to 25 ° C. and / or one of the liquid or soluble acid phosphates, and NH 4 EI ammonium hydroxide is added thereto. 2. A process according to claim 1, characterized in that at least one of the inorganic acids is phosphoric acid, orthophosphoric acid or pyrophosphoric acid. 3. A process according to claim 1, characterized in that the soluble phosphate is at least one of sodium phosphates and preferably potassium or ammonium. 4. A process according to claims 1 and 2 characterized in that the liquid or soluble acidic phosphate is at least one of the acid phosphates of zinc, ammonium or aluminum. 5. A process according to any one of claims 1 to 4, characterized in that it incorporates in acidic mother liquors solutions and / or phos # hatches of ammonium hydroxide.  6.- Application of the process according to claims 1,2,3 and 5 for obtaining a fertilizer solution consisting in diluting up to 1000 times in fresh water the dilutable fertilizing solution obtained. 7.- Application of the process according to claims 1,2,4 and 5 for obtaining an alkaline earth metal cement comprising mixing the crosslinking solution obtained with at least one oxide, hydroxide or metal carbonate alkaline earth, as well as traditional accelerator-type compounds, mineral, organic or vegetable fillers, or compatible fibers and dyes, and expanding agent as well as stabilizer and cell regulator.