RU2775737C2 - Production of mining processing product using polymers containing boronic acid - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: inventions relate to methods and compositions for improvement of characteristics of flocculating agents used in mining processes. Solid-liquid separation in a liquid flow of a mining process, having pH of 8 or more, includes addition to the liquid flow of polymer containing boronic acid, containing acrylamide and vinyl monomer, containing a boronic acid fragment selected from a group consisting of 3-(acrylamide)phenylboronic acid, 4-(acrylamide)phenylboronic acid, 2-(acrylamide)phenylboronic acid, 4-vinylphenylboronic acid, 3-vinylphenylboronic acid, 2-vinylphenylboronic acid and mixtures thereof, and polysaccharide – dextran with the separation of solid from the specified liquid flow.

EFFECT: inventions make it possible to increase the efficiency and effectiveness of the flocculant in industrial processes.

29 cl, 4 dwg, 1 tbl, 4 ex

Description

Field of invention

This invention relates, in General, to methods and compositions for improving the characteristics of flocculating agents used in industrial processes. More specifically, the invention relates to improving the use of flocculating agents such as dextran by pH-initiated cross-linking of flocculating agents with polymers containing boronic acid.

State of the art

Aluminum ore ('bauxite') is considered the main source of aluminium. On an industrial scale, bauxite is first processed into alumina (also known as "alumina(III) oxide", "aluminum hydroxide", "aluminum trihydrate" and "alumina"), which is then converted into aluminum metal. The main means of processing bauxite and producing aluminum hydroxide on an industrial scale is the well-established technology of the Bayer process.

In general, the Bayer process typically includes: a leaching step in which alumina is extracted by leaching bauxite ore in a sodium hydroxide solution ('caustic' or 'caustic') to form an aqueous solution of sodium aluminate; a purification step in which the solid phase residue ('red mud' or 'bauxite residue') is removed from the mother liquor (supersaturated sodium aluminate solution) by precipitation and filtration, leaving the sodium aluminate in solution; a decomposition step in which aluminum hydroxide is precipitated from a sodium aluminate solution ('liquid' or 'Bayer process' liquid) and grown as aluminum hydroxide crystals (crystallization); a classification step in which the seed crystals are separated from the aluminum hydroxide production material; and then a calcination step in which the aluminum hydroxide decomposes to form alumina, the final alumina product. A more detailed description of the Bayer process and its technological steps is widely presented in the literature. For example, a more detailed, but not exhaustive, description of the steps in the Bayer process is provided in US Pat. No. 8,298,508, which is incorporated herein by reference in its entirety.

Alumina production is energy intensive and costly. Although the Bayer process has been in use for more than a century, there are still many challenges to its improvement. Due to lower ore quality, greater mineral complexity and environmental concerns, there is an ongoing need for process optimization that can maximize product yield, provide energy savings and minimize production costs. Attempts to achieve these goals are hampered by many complicating factors, including impurity levels in the liquid, alkaline cracking at higher concentrations. Moreover, the specific technologies used in the industry for various process steps may vary from enterprise to enterprise, making system improvements difficult.

Particular areas of focus in terms of process optimization include maximizing fluid throughput/yield and reducing energy consumption. This includes a decomposition step in which the precipitated solid aluminum hydroxide is collected as a product using multiple decomposition and flocculation steps of the purified sodium aluminate solution. Maximizing the yield of aluminate crystals at this stage is important to increase the economic efficiency of obtaining aluminum in the Bayer process.

Bayer process operators strive to optimize their crystal formation and settling processes in such a way as to obtain the highest possible product yield from the Bayer process while still producing crystals of a given particle size distribution. Relatively large particle sizes are preferred for the subsequent processing steps required to produce aluminum metal. Undersized aluminum hydroxide crystals or fines are generally not used in aluminum metal production, instead they are recycled for use as fine aluminum trihydrate seeds. Therefore, the particle size of the precipitated trihydrate crystals determines whether the material is ultimately used as a production material (larger crystals) or as a seed (smaller crystals). Therefore, an important step in the Bayer process is the classification and selection of trihydrate particles of different sizes.

This separation or recovery of aluminum trihydrate crystals as a product of the Bayer process or for use as seed grains is typically carried out by one of a variety of techniques, including one of sedimentation, cyclonic separation, filtration, and/or a combination thereof. Large particles settle quickly, while small particles settle more slowly. Plants typically use two or three settling steps to classify trihydrate particles into different product and seed fractions. In particular, at the final stage of classification for the selection and sedimentation of fine seed grains, a settling tank is often used. The overflow from the last stage of classification is returned to the process as waste liquid for use in leaching. The trihydrate particles entering the overflow during this last settling step are usually not used in the process either as a seed or as a product. In fact, such material circulates in the process, reducing its efficiency. The particle size of the precipitated trihydrate crystals obtained at the stage of classification and selection of trihydrate particles, regardless of whether the material is ultimately to be used as a product or as a seed, and minimizing the amount of aluminum trihydrate fines in the overflow have a direct impact on the quality and volume of alumina yield. . Therefore, further improvement of efficiency in this part of the process remains an open-ended goal.

In an attempt to increase the efficiency of the aluminum trihydrate separation process, certain compounds are added to the process as additives, including various flocculants that are soluble or dispersible in the process fluid, such as the polysaccharide dextran. In order to improve the settling characteristics of the aluminum trihydrate particles during the classification process and therefore reduce the amount of solids in the waste fluid, conventional technology uses the addition of synthetic water-soluble polyacrylate flocculants and/or dextran flocculants. Cross-linked dextran or cross-linked dihydroxypropyl cellulose are also used to improve the precipitation characteristics of fine aluminum trihydrate crystals. Although such treatments involving flocculating compositions are often used in Bayer line trihydrate classification systems, some of them are time-consuming to manufacture, have limited use and are associated with shipping costs, and these factors together have a negative impact on efficiency and increase costs.

Despite the continuous and constant development of methods suitable for obtaining crystals of aluminum hydroxide with increased particle size, there is still a need for improvements and improvements in the process for the production of aluminum hydroxide, in order to eliminate problems associated with quality and economic efficiency. There is a need and need for methods and compositions that improve particle recovery and settling rates while minimizing the concentration of solids in the overflow after the last classification step. Together, these improvements improve process efficiency, reduce preparation time and material usage, and provide application flexibility.

The prior art described in this section is not intended to be an admission that any patent, publication, or other information referred to in this document constitutes "prior art" with respect to this invention, to the extent that it not specifically stated. In addition, this section should not be construed to mean that a study has been performed or that no other significant information exists, as defined in 37 CFR 1.56(a).

The essence of the invention

In at least one embodiment, the invention relates to methods and compositions for improving the efficiency and effectiveness of a flocculant in industrial processes. The methods include a pH-driven rapid crosslinking reaction between a flocculating agent such as a polysaccharide, eg dextran, and a composition containing a boronic acid-containing polymer. The pH boost can be created by the inherent alkalinity of the working fluid to be treated, allowing preparation and cross-linking at the production site and at the point of use, resulting in increased efficiency and reduced production costs.

In at least some embodiments, the present invention includes a process for solid-liquid separation in a mining process to produce a mining product at a manufacturing site. The method includes combining a first composition containing a flocculating agent and a second composition containing a polymer containing boronic acid to form a mixture. The method further includes initiating a crosslinking reaction between the flocculating agent and the boronic acid-containing polymer by exposing the mixture to an alkaline medium at a pH of 8 or more, which results in the formation of a reaction product. In some embodiments of the invention, the pH is 10 or more. The reaction product is used on the site as a flocculant in a mining process fluid stream at one or more locations where solid/liquid separation occurs.

In these and other exemplary embodiments, the method may further include introducing the reaction product into the liquid stream. In some embodiments of the invention, the introduction of the reaction product is carried out by feeding it into the liquid stream, and the crosslinking reaction is initiated at the production site before filing. In some embodiments of the invention, the reaction product is introduced by feeding the mixture into a liquid stream, wherein the crosslinking reaction is initiated in a liquid stream (in situ) having a pH of 8 or greater. In some embodiments of the invention, the reaction product is introduced by feeding the first and second compositions into the liquid stream, and the mixture is formed in the liquid stream (in situ) and the crosslinking reaction is initiated by the pH of the liquid stream (8 or more), which leads to the formation of the reaction product.

In various embodiments, the mining or manufacturing process is a Bayer process for producing alumina from bauxite ore and the fluid is a liquid caustic or slurry in the Bayer process fluid loop. In some embodiments of the invention, methods and compositions refer to the use, as a trihydrate flocculant, the product of pH-initiated crosslinking of a flocculating agent, which may be a polysaccharide, such as dextran, with a polymer containing boronic acid. The flocculant improves line performance and accelerates the settling of fine aluminum hydroxide crystals (bottom drain solids) in Bayer liquid caustic. The pH-driven crosslinking reaction between dextran and a polymer containing boronic acid, the product of which is intended to flocculate solid particles of aluminum trihydrate in liquid Bayer caustic, proceeds rapidly. This makes it possible to prepare and use the flocculant at the production site or on site. This provides a significant reduction in time compared to traditional dextran crosslinking technology and increases the concentration of the active ingredient in the final product, and thus significantly reduces transportation costs.

In at least some embodiments of the invention, the manufacturing process is a Bayer process for producing alumina. A flocculating agent, in some embodiments, a polysaccharide, and a second composition containing a polymer containing boronic acid, are mixed and combined with a batch of liquid or suspension with a pH of at least 8 and, in some embodiments, 10, from the Bayer process. Once combined, the pH level initiates a rapid crosslinking reaction between the polysaccharide and the boronic acid containing polymer to form a reaction product for use in the Bayer process fluid stream at one or more locations where solid-liquid separation occurs. In some embodiments of the invention, the polysaccharide is dextran. In other embodiments of the invention, the boronic acid-containing polymer is in the form of a latex, an aqueous solution, or a dry powder.

In at least one embodiment of the invention, a portion of the liquid or slurry removed from the liquid stream and then combined with the first and second compositions, after connection, is added to the Bayer process liquid stream channel; or the first and second compositions are combined with a portion of the liquid or slurry in a Bayer process liquid flow channel.

In this and various other embodiments, the boronic acid-containing polymer is the reaction product of the polymerization of at least one water-soluble vinyl monomer and at least one vinyl monomer containing a boronic acid moiety, which, in various embodiments, is phenylboronic acid.

In this and various other embodiments of the invention, at least one vinyl monomer containing a boronic acid moiety may be selected from the group consisting of 3-(acrylamido)phenylboronic acid, 4-(acrylamido)phenylboronic acid, 2-(acrylamide) phenylboronic acid, 4-vinylphenylboronic acid, 3-vinylphenylboronic acid, 2-vinylphenylboronic acid, and mixtures thereof. In some embodiments of the invention, at least one water-soluble vinyl monomer may be an acrylate monomer or may be selected from the group consisting of acrylamide; acrylic acid or its salts; 2-acrylamido-2-methylpropanesulfonic acid or salts thereof; N , N , N -trimethyl-2-[(1-oxo-2-propenyl)oxy]-ethanamine chloride, N , N -dimethyl- N -propenyl-2-propene-1-aminium chloride and mixtures thereof.

In at least one embodiment of the invention, the vinyl monomer containing the boronic acid moiety is 3-(acrylamido)phenylboronic acid. In this and various other embodiments of the invention, the water-soluble vinyl monomer is acrylamide. In at least one embodiment of the invention, the boronic acid-containing polymer is a water-soluble polyacrylamide containing boronic acid.

In this and various other embodiments, the boronic acid-containing polymer has a reduced specific viscosity of at least about 0.2 dl/g. In this and various other embodiments of the invention, the polymer containing boronic acid may contain at least 0.01% wt. boronic acid monomer. In some embodiments of the invention, the mixture of the first and second compositions contains at least 0.01% wt. polymer containing boronic acid.

In this and various other embodiments of the invention, the polymer containing boronic acid may contain at least 0.01% wt. boronic acid monomer. In other embodiments of the invention, the polymer containing boronic acid may contain from about 1.0% wt. up to about 2.0% wt. boronic acid monomer and, in some embodiments of the invention, contains at least about 0.01% wt. mixtures.

In this and various other embodiments of the invention, the duration of the crosslinking reaction may be about 30 minutes or less.

In this and various other embodiments of the invention, the boronic acid-containing polymer may comprise a biopolymer, a synthetic polymer, or mixtures thereof. In some embodiments of the invention, the polymer containing boronic acid is a water-soluble polyacrylamide containing boronic acid. The polyacrylamide can be prepared by radical polymerization of acrylamide and at least one vinyl monomer containing a boronic acid moiety. In other embodiments, the boronic acid-containing polymer may be polymerized using a monomer selected from the group consisting of acrylic acid or salts thereof, 2-acrylamido-2-methylpropane sulfonic acid (AMPS) or salts thereof, 2-( acryloyloxy) -N , N , N -trimethylethanamine (DMAEA.MCQ). In some embodiments, the boronic acid monomer is 3-(acrylamido)phenylboronic acid (APBA). In various embodiments of the invention, the polymer containing boronic acid is non-ionic, anionic, cationic, amphoteric or associative. The boronic acid-containing polymer may be linear or non-linear; and stitched or not stitched. In some embodiments, the boronic acid-containing polymer is in the form of a latex, an aqueous solution, or a dry powder.

In some embodiments of the invention, the reaction product is introduced into the Bayer process fluid, thereby increasing the recovery of aluminum hydroxide from the aluminum trihydrate production process. The reaction product may be introduced into the Bayer process fluid at one or more locations and, for this reason, it will provide improved flocculation of the trihydrate particles compared to using non-crosslinked dextran. In addition, the reaction product may be introduced into the Bayer process fluid at one or more locations and, for this reason, it will reduce the rate of nucleation of one or more aluminum trihydrate crystals in the process. The invention further includes embodiments in which the reaction product may be introduced into the Bayer process fluid or slurry at one or more locations to expedite red mud cleanup in the process.

In at least one embodiment of the invention, a method is disclosed that focuses on the deposition of aluminum trihydrate in the Bayer process. The method includes adding a sufficient amount of a trihydrate flocculant to the Bayer process fluid. The trihydrate flocculant is prepared by combining a polysaccharide, a polymer containing boronic acid, and a portion of a liquid or slurry to form a crosslinked reaction product. In some embodiments of the invention, the polysaccharide is dextran, and the reaction product is formed as a result of pH-initiated liquid or slurry cross-linking of dextran with polymers containing boronic acid. The pH level required to initiate crosslinking may be present in the Bayer process liquid or slurry. The use of a trihydrate flocculant results in increased flocculation of aluminum hydroxide particles and a reduced solids content in the overflow.

At least one embodiment of the invention is directed to a process for precipitating aluminum trihydrate in a Bayer process system. The method includes adding a sufficient amount of cross-linked dextran to the system. Crosslinking is the result of an in situ reaction of dextran with a composition comprising boronic acid containing polymers, wherein the dextran and the boronic acid containing polymer composition are combined in a solution having a specific pH, and this pH initiates the crosslinking reaction. In some embodiments of the invention, the solution is a portion of the liquid from the Bayer process system. In this and various other embodiments of the invention, dextran and the boronic acid-containing polymer composition are combined in a fluid stream of a Bayer process system. The use of such dextran/boronic acid crosslinked polymer flocculants results in improved precipitation of aluminum hydroxide compared to conventional flocculants used in this process.

A solution of dextran crosslinked with a polymer containing boronic acid can be added to the Bayer process fluid in a trihydrate classification loop during alumina production. The solution may be added to the liquid at one or more locations in the process loop in which solid-liquid separation occurs. The additional locations may help to reduce the rate of nucleation of one or more aluminum hydroxide crystals in the process. Additional locations may help to reduce the rate of deposit formation in the process. The solution can further increase the yield in the isolation of aluminum trihydrate.

In the above and various other embodiments of the invention, the Bayer process is carried out at alumina production facilities, and the crosslinking of dextran with polymers containing boronic acid is carried out at alumina production facilities. In various embodiments of the invention, the crosslinking is carried out in a portion of the Bayer process liquid. In some embodiments, dextran is crosslinked with boronic acid containing polymers in a portion of the Bayer process liquid caustic removed from the Bayer process liquid stream and then added to the Bayer process liquid stream. In some embodiments, the dextran composition and the boronic acid polymer composition are combined and added to the Bayer process fluid stream.

In these and various other embodiments, crosslinking a flocculating agent such as dextran with polymers containing boronic acid significantly reduces the working time required to crosslink the dextran compared to crosslinking with conventional agents such as those containing epichlorohydrin. The pH levels of the liquid caustic of the Bayer process initiate a rapid crosslinking reaction between the dextran and polymers containing boronic acid to flocculate the aluminum trihydrate solids. In some embodiments of the invention, the duration of crosslinking in the preparation of an improved flocculant is 1-30 minutes, which is significantly less than in the case of commercial products, when it is 1-20 hours. Cross-linking dextran with polymers containing boronic acid can further increase the effective concentration of the product, which reduces transport costs and overall manufacturing costs.

Further advantages of the compositions and methods of the present invention include, but are not limited to, reducing costs associated with the aluminum hydroxide manufacturing process while improving the efficiency and effectiveness of the manufacturing process. These methods and compositions help to maximize the efficiency of the process and achieve the lowest possible concentration of solids in the overflow of the last stage of classification.

An additional advantage of cross-linking dextran with polymers containing boronic acid in alumina production facilities to produce trihydrate flocculant, which is used in the precipitation of aluminum trihydrate in the Bayer process, is that it can increase flocculation efficiency, reduce reaction time, increase the maximum effective dose , accelerate settling and improve the shear resistance of the trihydrate flocculant. In addition, the cross-linking of dextran with polymers containing boronic acid at the production site or on site at the alumina production facility provides a reduction in transportation and production costs.

In at least one embodiment of the invention, the mining process is an iron ore processing process, and the separation of the solid and liquid phases is the separation of iron ore tailings. Similarly, the method includes combining a flocculating agent and a second composition containing a polymer containing boronic acid to form a mixture; and initiating a crosslinking reaction between the flocculating agent and the boronic acid-containing polymer by exposing the mixture to an alkaline medium at a pH of 8 or more, whereby a reaction product is formed. The reaction product is used at the production site as a flocculant in the liquid stream of the iron ore processing process at one or more sites where separation into solid and liquid phases occurs.

Likewise, the method described above further comprises feeding the reaction product into the liquid stream, wherein the crosslinking reaction is initiated at the production site before being fed; feeding the mixture into a liquid stream that has a pH level of 8 or more, wherein the crosslinking reaction is initiated in the liquid stream; or feeding the first and second compositions into a liquid stream that has a pH level of 8 or more, wherein the mixture is formed and the crosslinking reaction is initiated in the liquid stream. As described above, the boronic acid-containing polymer is the reaction product of at least one water-soluble vinyl monomer and at least one vinyl monomer containing a boronic acid moiety.

In at least some embodiments, the present invention includes a flocculating composition for solid-liquid separation in a Bayer process for producing alumina. The flocculant contains the product of a pH-initiated crosslinking reaction between the flocculating agent and the polymer containing boronic acid. The crosslinking reaction is initiated by exposing the mixture of the flocculating agent with the polymer containing boronic acid to an alkaline environment with a pH level of 8 or more, wherein the polymer containing boronic acid is the polymerization reaction product of at least one water-soluble vinyl monomer and at least one vinyl monomer, containing a fragment of boronic acid.

In some embodiments of the invention, the polymer containing boronic acid has a reduced specific viscosity of at least about 0.2 dl/g and contains at least about 0.01% wt. monomer with boronic acid. In this and various other embodiments of the invention, the polymer containing boronic acid may contain from about 1.0% wt. up to about 2.0% wt. monomer with boronic acid contains at least about 0.01% wt. mixtures . In other embodiments of the invention, the polymer containing boronic acid contains from 0.10% wt. up to about 10% wt. mixture, and the crosslinking reaction time is about 30 minutes or less. In at least some embodiments of the invention, the flocculating composition promotes the formation of crystalline agglomerates during crystallization from the precipitating liquid.

In at least one embodiment of the invention, a sales kit is disclosed, which includes a composition with a polymer containing boronic acid and a printed leaflet. The printed package insert states that the composition can be used as an additive for separating solid and liquid phases in a mining process. In some embodiments, the printed package insert indicates that the boronic acid-containing polymer is a polymerization reaction product of at least one water-soluble vinyl monomer and at least one vinyl monomer containing a boronic acid moiety. The printed leaflet indicates to the user or orients him to the instructions for use of the composition. The instruction may indicate a method of separating into solid and liquid phases in a mining process for the production of a mining product at a production site, as disclosed in this document.

In at least some embodiments, the instruction indicates that the method includes combining a first composition containing a flocculating agent and a composition containing a polymer containing boronic acid to form a mixture. Said method further comprises initiating a crosslinking reaction between the flocculating agent and the boronic acid-containing polymer by exposing the mixture to an alkaline medium at a pH of 8 or more, which results in the formation of a reaction product. The instruction may additionally indicate that the reaction product is used at the production site as a flocculant in the liquid stream of the mining process at one or more sites where separation into solid and liquid phases occurs.

In at least some embodiments, the instruction further indicates that the method includes feeding the reaction product into the liquid stream, wherein the crosslinking reaction is initiated at the production site prior to feeding; feeding the mixture into a liquid stream that has a pH level of 8 or more, wherein the crosslinking reaction is initiated in the liquid stream; or feeding the first and second compositions into a liquid stream that has a pH level of 8 or more, wherein the mixture is formed and the crosslinking reaction is initiated in the liquid stream.

In these and various other embodiments of the invention, the mining process is a Bayer process and the mining product is alumina. The printed package insert describes the use of the composition as an additive in Bayer solid-liquid separation and provides instructions on the Bayer process solid-liquid separation process for on-site alumina production. In various other embodiments of the invention, the mining process is an iron ore processing process. The printed package insert describes the use of the composition as an additive in solid-liquid separation in iron ore processing and provides instructions for the solid-liquid separation process in iron ore processing at an iron ore production site.

The above summary of the various aspects of the invention is not intended to describe every illustrated aspect or every embodiment of the invention. From the following detailed description, those skilled in the art will easily understand other objects and advantages of the present invention and methods for forming them. As will be shown, the invention is capable of other and various embodiments and ways of forming them, and some of its parts are amenable to modification in various obvious respects, all without departing from the scope of the invention. Accordingly, the graphics and description are to be taken as illustrative in nature and not as restrictive.

Brief description of graphic materials

In the following detailed description, special reference is made to the drawings in which:

FIG. 1 is a plot of sample comparison results in the overflow solids reduction test.

FIG. 2 is a graph of sample comparison results in the overflow solids reduction test.

FIG. 3 is a graph of the results of comparing additive samples in the red mud settling test.

FIG. 4 is a graph of the results of comparing additive samples in the iron ore tailings settling test.

Although various modifications and alternatives are possible in this invention, its specificity is presented by way of examples in the drawings, and will be described in detail. However, it should be understood that there is no intention to limit the present invention to particular aspects. On the contrary, the aim is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined in the appended claims.

Detailed description of the invention

While the invention may be embodied in many different forms, specific embodiments of the invention are described in detail herein. This description is illustrative of the principles of the invention and is not intended to limit the invention to the particular illustrated embodiments.

The following are definitions applicable to significant terms that are used in this specification. The classification of definitions is for convenience only and is not intended to limit any definitions to any particular category.

"Consisting essentially of" means that the methods and compositions may include additional steps, components, ingredients, or the like, but only in cases where the additional steps, components, and/or ingredients do not significantly change the basic and new characteristics of the claimed methods and compositions.

"Dextran" is a glucose-linked α-D-1,6 glucan with side chains 1-3 linked to units of the biopolymer backbone.

"Dihydroxypropylcellulose" is a cellulose derivative with a 1,2-dihydroxypropyl ether group added to the cellulose backbone.

"Liquid" or "Bayer Fluid" means a caustic fluid that passes through at least part of the Bayer process at a commercial facility.

"Settling feed liquid" means the settling liquid which enters the settling tank of the aluminum hydroxide precipitation process.

The "precipitating liquid" means an aluminate-containing liquid in the aluminum hydroxide precipitation step of the alumina production process. Aluminate liquid may be referred to by various terms known to those of ordinary skill in the art, such as mother liquor, aluminate liquor, and aluminum hydroxide precipitation feedstock. The Bayer process is one example of an alumina production process. The term precipitating liquid may also encompass an aluminate solution directed to decomposition into a sinter-carbonization or combined Bayer-sinter process as completed by methods well known to those skilled in the art, as described, for example, in US Pat. , 2257347 and 2181695.

"Product Yield" refers to the amount of aluminum hydroxide solids contained within the settling tank at the end of the settling cycle. An increased yield of product is usually indicated by a lower concentration of aluminum hydroxide in the liquid in the appropriate container.

"Slurry" means a mixture containing a liquid medium in which fines (which may be liquid and/or finely divided solids) are dispersed or suspended, when the slurry is sparged, the ore tailings remain in slurry and at least a portion of the concentrate adheres to the sparged bubbles and rises from slurry upwards, into a layer of foam above the slurry, the liquid medium may consist entirely of water, partially consist of water, or contain no water at all.

"Waste liquid" refers to the liquid that remains after the removal of the precipitated volumes of aluminum after the final stage of classification, which is returned back to be leached in the Bayer process.

As used herein, "Referred Specific Viscosity" or "RSV" refers to specific viscosity divided by concentration, specifically measured at concentrations of 0.45 g of polymer in a one normal sodium nitrate solution.

"Concentrator" or "Settler" means a container that is used to influence the separation of a suspension into solid and liquid phases, which is often carried out with the addition of flocculants, the container is designed and adapted to receive the suspension, holding the suspension for a period of time sufficient to allow the solid phases of the suspension to settle down (bottom drain) from the more liquid part of the slurry (top drain), overflow the top drain and remove the bottom drain. The bottom overflow and overflow from the concentrator are often fed to filters to further separate the solid phase from the liquid phase.

"Percentage by weight" refers to the total mass fraction of a reactant in 100 g of a composition or mixture.

In the event that the above definitions or the description set forth elsewhere in this application are incompatible with the meaning (whether directly or indirectly) that is commonly used, given in a dictionary or set forth in a source introduced into this application by reference, the terms in the application and the Formula inventions, in particular, should be construed in accordance with the definition or description given in this application, and not in accordance with the usual definition, dictionary definition or definition that has been introduced by reference. In light of the foregoing, if a term can only be understood if it is interpreted in a dictionary, if the term is defined in the Kirk-Othmer Encyclopedia of Chemical Technology , 5th Edition, (2005), (Published by Wiley, John & Sons, Inc.), that definition will be indicate how the term should be defined in the claims.

This document describes methods and compositions that use polymers containing boronic acid to improve the efficiency of the flocculant and the productivity of the industrial process. In at least some embodiments, the boronic acid-containing polymer component (or "boronic polymer component") is combined with the flocculating agent component (or "flocculating agent component") at the manufacturing site or on site to form a mixture. The mixture is combined with or introduced into an alkaline liquid having a pH of 8 or more. The pH of the alkaline liquid initiates a crosslinking reaction between the flocculating agent component and the boronic polymer component, resulting in the formation of a reaction product. The initiation may be before or after the introduction of an industrial process, such as the Bayer process, into the fluid stream. The reaction product is used in the separation of solid and liquid phases in an industrial process.

In the methods disclosed herein, the pH-triggered reaction, whether prior to in-line or in-situ injection/application, is an improvement over the longer preparation and reaction times of other flocculants, flocculating agents, or flocculation methods. The methods of administration of the invention provide greater flexibility and the ability to make rapid changes in the replenishment of various dosage prescriptions. The methods further provide a reduction in transportation and storage costs.

In at least some embodiments, the reaction between the flocculant components, such as the boronic acid-containing polymer and dextran, or the crosslinking, is carried out in situ . In other words, the components of the flocculant are supplied separately, and the reaction between them or the crosslinking in the liquid flow is carried out at the place of use to form the flocculant. The components of the flocculant are mixed and added to the fluid flow of the manufacturing process of a particular facility. A fluid flow pH of 8 or more initiates crosslinking of the mixed flocculant components. In the case of the Bayer process, in some embodiments, the flocculant components are added to the Bayer fluid in the trihydrate classification loop during the production of aluminum trihydrate. The flocculant components may be added to the liquid at one or more locations in the Bayer process loop in which solid-liquid separation occurs.

In some embodiments of the invention, the reaction or crosslinking includes mixing the components with a portion of an alkaline solution having a pH of 8 or more, for example, a portion of the fluid flow of the manufacturing process of a particular object. The pH of the alkaline solution initiates crosslinking of the flocculant components, forming polymers containing boronic acid. The reacted or cross-linked flocculant components are then added directly to the liquid stream. In the case of the Bayer process, in some embodiments of the invention, a portion of the alkaline Bayer liquid from the liquid stream in the process line of the Bayer process can be used. The reacted or cross-linked flocculant components in a portion of the alkaline Bayer liquid are then added directly to the Bayer liquid in the trihydrate classification circuit during the production of aluminum trihydrate. The flocculant components may be added to the liquid at one or more locations in the Bayer process loop in which solid-liquid separation occurs.

In at least one embodiment of the invention, the flocculant components are added to the liquid in the trihydrate classification loop during the production of aluminum trihydrate. The flocculant components may be added to the liquid at one or more locations in the Bayer process loop in which solid-liquid separation occurs. In at least one embodiment, the flocculant components may be added to said fluid at one or more locations in the Bayer process line where they reduce the rate of nucleation of one or more aluminum hydroxide crystals in the process. In at least one embodiment of the invention, the flocculant components may be added to the liquid at one or more locations in the Bayer process line where they reduce the rate of deposit formation in the process. In at least one embodiment of the invention, the flocculant components may be added to the fluid at one or more locations in the Bayer process line where they accelerate red mud cleanup in the process.

Flocculant components

In at least some embodiments, the flocculant components include a flocculating agent or flocculating agent component, which, in typical embodiments, is a polysaccharide, and a boronic polymer component, which, in typical embodiments, is a polymer containing boronic acid. In response to the pH push, the components undergo a crosslinking reaction, which results in the formation of a flocculating composition. In some embodiments of the invention, the duration of crosslinking in the preparation of an improved flocculant is 1-30 minutes. The efficiency of the pH-initiated crosslinking of the present invention allows this reaction to be carried out on site or in situ , while conventional crosslinking of polysaccharides is performed off-site within 1-20 hours. The cross-linked flocculating composition acts as an additive to the process to promote settling and the efficiency of the separation process. In some different embodiments of the invention, the pH initiator may be a solution having a pH of 8 or higher, including process fluid from an industrial process. In some embodiments, the industrial process is a Bayer process and cross-linked flocculant components are used in the process fluid to promote the settling of fine aluminum hydroxide crystals and reduce the amount of solids in the waste fluid.

Flocculating agent component

In various embodiments, the flocculating agent component comprises a flocculating agent, which, in at least some embodiments, may be a synthetic polymer, a polysaccharide, or mixtures thereof. In some embodiments of the invention, the flocculating agent contains one or more polysaccharides. The polysaccharides may contain glucose monosaccharides, including, for example, one of or a mixture of dextran, starch, guar gum, dihydroxypropyl cellulose, pullulan, scleroglucan, zooglan, lactam, ramzan, etc. In at least some embodiments, the flocculating agent is soluble or dispersible in the process fluid, such as dextran in the Bayer process fluid, and can be added alone as an additive to the process.

Boron polymer component

In various embodiments, the boronic polymer component comprises one or more boronic acid containing polymers (or "boronic polymer(s)") and may be a biopolymer or a synthetic polymer. The boronic acid-containing polymer can be synthesized from or be the product of a polymerization reaction, such as free radical polymerization, of at least one water-soluble vinyl monomer and at least one vinyl monomer containing a boronic acid moiety ('boronic acid monomer').

In at least some embodiments, examples of suitable water-soluble vinyl monomers include acrylamide; acrylic acid or its salts; 2-acrylamido-2-methylpropane sulfonic acid or salts thereof (AMPS or ATBS); N , N , N -trimethyl-2-[(1-oxo-2-propenyl)oxy]-ethanamine chloride (DMAEA.MCQ), N , N -dimethyl- N -propenyl-2-propene-1-aminium chloride (DADMAC) and their mixtures.

In at least some embodiments, the boronic acid monomer contains at least one vinyl group and a boronic acid moiety. In this and various other embodiments of the invention, the boronate moiety is supplied with substituted phenylboronic acids (PBAs). Examples of suitable boronic acid monomers include, but are not limited to, 3-(acrylamido)phenylboronic acid (APBA), 4-(acrylamido)phenylboronic acid, 2-(acrylamide)phenylboronic acid, 4-vinylphenylboronic acid, 3-vinylphenylboronic acid, 2 -vinylphenylboronic acid; and mixtures thereof.

In these and various other embodiments of the invention, the synthesized polymer containing boronic acid may have one or more of the following properties: nonionic, anionic, cationic, amphoteric and associative. In addition, the polymer containing boronic acid may be linear or non-linear; and may be crosslinked or uncrosslinked.

In some embodiments of the invention, including embodiments used in the Bayer process, the boronic polymer is a polyacrylamide containing boronic acid. Polyacrylamide can be prepared by radical polymerization of acrylamide (a water-soluble vinyl monomer) and a boronic acid monomer (at least one vinyl monomer containing a boronic acid moiety).

In the above and various other embodiments of the invention, the water-soluble vinyl monomer (acrylamide) can be replaced or combined with a water-soluble vinyl monomer selected from the group consisting of: acrylic acid or its salts, 2-acrylamido-2-methylpropane sulfonic acid ( AMPS) or its salts, 2-(acryloyloxy) -N,N,N -trimethylethanamine (DMAEA.MCQ), N,N -dimethyl- N -propenyl-2-propene-1-aminium chloride (DADMAC) and mixtures thereof.

In the above and various other embodiments, the boronic acid monomer may be 3-(acrylamido)phenylboronic acid (APBA), 4-(acrylamido)phenylboronic acid, 2-(acrylamide)phenylboronic acid, 4-vinylphenylboronic acid, 3 -vinylphenylboronic acid, 2-vinylphenylboronic acid or mixtures thereof.

In at least one embodiment of the invention, the boron polymer is obtained by radical polymerization of a water-soluble vinyl monomer and APBA. In this and various other embodiments of the invention, the water soluble vinyl monomer may be selected from the group consisting of: acrylamide (AM), acrylic acid or its salts (AA), 2-acrylamido-2-methylpropane sulfonic acid or its salts (AMPS or ATBS), 2-(acryloyloxy) -N,N,N -trimethylethanamine (DMAEA.MCQ), N,N -dimethyl- N -propenyl-2-propene-1-aminium chloride (DADMAC) and mixtures thereof.

In at least some embodiments, the boronic polymer contains at least 0.01% boronic acid monomer. In other embodiments of the invention, the boron polymer contains from about 0.5% wt. up to about 2.5% wt. monomer with boronic acid, the rest contains water-soluble vinyl monomer(s). In at least some embodiments, the boron polymer contains from about 1.0% wt. up to about 2.0% wt. monomer with boronic acid. In some embodiments of the invention, the boron polymer contains from 1.0% wt. up to about 2.0% wt. monomer with boronic acid and from about 98.0% wt. up to about 99% wt. water-soluble vinyl monomer(s).

In this and various other embodiments, the boron polymer component may have an RSV in the range of about 0.2 dl/g to about 50 dl/g. In some embodiments of the invention, the range is from about 0.2 dl/g to about 35 dl/g. In other embodiments of the invention, the range is from about 1.0 dl/g to about 35 dl/g. In other embodiments of the invention, the range is from about 5 dl/g to about 30 dl/g.

The boronic acid-containing polymer may be supplied or delivered in various forms. Examples of such forms include latex, aqueous solution or dry powder.

Mixture of flocculant components

The flocculating agent component and the boron polymer component are combined to form a mixture. In at least some embodiments, the mixture is formed by preparing a portion of the flocculating agent component and a portion of the boron polymer component, and combining the components at a production site at a mining site. In some embodiments of the invention, the mixture is formed outside the liquid flow of the manufacturing process. In some other embodiments of the invention, the mixture is formed in situ by adding the two components directly into the fluid stream of the manufacturing process. In other embodiments of the invention, the mixture is received or delivered to the production site. In at least some embodiments of the invention, the components of the mixture remain unreacted until the reaction is initiated by pH.

In at least some embodiments of the invention, the mixture contains from about 0.01% wt. up to about 50% wt. boron polymer component, the rest is a flocculating agent component. In some embodiments of the invention, the mixture contains from about 0.01% wt. up to about 30% wt. boron polymer component. In other embodiments of the invention, the mixture contains from about 0.10% wt. up to about 10% wt. boron polymer component. In at least some embodiments of the invention, blends with a boronic polymer component having a higher RSV contain amounts of the boronic polymer component from the lower portions of the ranges.

Flocculant Crosslinking Reaction

Subsequently, the mixture is exposed to an alkaline environment with a pH of 8 or more to initiate a crosslinking reaction between the flocculating agent component and the boron polymer component. In some embodiments of the invention, the mixture is initiated by exposing it to a pH of 10 or more. After exposure, the components enter into a crosslinking reaction to form a flocculating composition. In some embodiments of the invention, the reaction time or the duration of crosslinking in the preparation of an improved flocculant is 1-30 minutes, which is significantly less than in the case of commercial products, when it is 1-20 hours.

In at least some embodiments, a flocculant is made by forming a mixture and then introducing the mixture into a manufacturing process fluid stream at one or more locations where solid-liquid separation occurs. The crosslinking reaction of the components of the mixture to form a flocculant is initiated in situ by exposure to an alkaline medium of pH 8 or more in the liquid stream.

In at least some embodiments of the invention, both the formation of the mixture of components and the initiation of the reaction of cross-linking of the components of the mixture by exposure to an alkaline environment with a pH of 8 or more in the liquid stream is carried out in place. In this case, the flocculant is made by introducing the first and second components separately into the liquid stream of the manufacturing process at one or more locations where solid-liquid separation occurs. The components are introduced in such a way that the first and second components are mixed in the liquid flow. As a result, the mixture is formed in the liquid flow. The liquid stream has a pH of 8 or more, therefore, it initiates a crosslinking reaction of the components, which results in the formation of a flocculant.

In some embodiments of the invention, the formation of the mixture and the initiation of the crosslinking reaction of the components of the flocculant in the mixture is carried out before being introduced into the fluid stream of the manufacturing process. In some embodiments of the invention, the components of the flocculant are exposed to an alkaline environment with a pH of 8 or more during the formation of the mixture. In some embodiments of the invention, the mixture of flocculant components is first formed and then exposed to an alkaline environment with a pH of 8 or more. After or during the crosslinking reaction, the mixture is introduced into the liquid stream of the manufacturing process at one or more locations where solid-liquid separation occurs.

In some embodiments of the invention, initiation of the crosslinking reaction of the flocculant components prior to introduction into the process fluid stream is accomplished by combining a portion of a solution having a pH of 8 or greater with the flocculant components or a mixture of flocculant components. In some embodiments of the invention, the solution is added to one or both components, with the components subsequently combined. In at least some embodiments of the invention, the solution having a pH of 8 or higher is a portion of the liquid from the manufacturing process. In some embodiments of the invention, the industrial production process is a Bayer process, and the fluid used as the initiator is a process fluid.

In some embodiments, a mixture of boronic acid-containing polymer and flocculating agent can be created, in which the boronic acid-containing polymer and flocculating agent in the mixture are unreacted, and this mixture can be delivered to the site of use. The mixture can be initiated by pH outside the liquid stream and then introduced into it, or the mixture is introduced directly into the liquid stream, so that the pH-initiated crosslinking occurs in situ.

In at least some embodiments of the invention, the industrial process is a Bayer process for producing alumina from bauxite ore. In these and various other embodiments, the invention relates to the use of a trihydrate flocculant to improve the performance of aggregates in the Bayer process, in particular to promote the precipitation of fine aluminum hydroxide crystals. The trihydrate flocculant can be made by pH-initiated cross-linking of dextran with polymers containing boronic acid. The crosslinking can be done on site or in situ using a Bayer process fluid as the pH initiator.

In at least one embodiment of the invention, the cross-linked dextran and the boronic acid-containing polymer are mixed by adding the boronic acid-containing polymer to the dextran to form a solution in which the boronic acid-containing polymer and the dextran are substantially unreacted. . The unreacted solution is then added to an alkaline solution containing sodium hydroxide, potassium hydroxide, or other alkali metal hydroxides, or a water-soluble alkali metal hydroxide and having a pH in the range of 8 to 14. The pH of the alkaline solution initiates a crosslinking reaction between the boronic acid-containing polymer and dextran. In some embodiments of the invention, the solution becomes a high viscosity solution or paste. In some embodiments of the invention, a suitable degree of crosslinking is achieved, as determined by measuring the increase in the viscosity of the solution.

In some embodiments of the invention, the use of the methods described herein increases the production and recovery of crystalline agglomerates from the precipitation liquid of the crystallization process. The use of crosslinked dextran in accordance with the present invention leads to an increase in the particle size of the recovered crystalline agglomerates compared to other conventional methods.

Embodiments of the invention further encompass a process for producing aluminum hydroxide from a Bayer process fluid containing an aqueous phase of sodium aluminate. The liquid can be produced by separating alkaline-insoluble suspended solids. The method may include the steps of (i) introducing portions of dextran and a polymer containing boronic acid, in accordance with this invention, in the precipitation liquid of the Bayer process and distributing them in the precipitation liquid; and (ii) settling crystalline agglomerates from the settling liquid. In this process, dextran and boronic polymer are added in an amount sufficient to shift the particle size distribution of the aluminum hydroxide crystals such that there is reduced fines formation in the resulting crystals.

In embodiments of the methods, dextran and polymers containing boronic acid can be added in accordance with the methods of this invention to the precipitation liquid in one or more of the following phases of the Bayer process: (i) to the supplied precipitation liquid; (ii) to seed slurry; (iii) to a precipitator; and (iv) into the inlet stream of the settling tank. In some embodiments of the invention, the components are distributed within the settling liquid by conventional high shear mixing or ultrasonic mixing.

In some embodiments of the invention, the components added in accordance with the present invention in the Bayer process for the production of aluminum hydroxide crystals, lead to reduced production of product fines in parallel with an upward shift in the particle size distribution of aluminum hydroxide, without significantly reducing the overall yield of aluminum hydroxide.

In at least one embodiment of the invention, this invention includes a set of chemical additives for separation into solid and liquid phases in the Bayer process for the production of alumina. The set of chemical additives includes: a first composition containing a polysaccharide and a separate second composition containing a polymer containing boronic acid. Between the polysaccharide and the polymer containing boronic acid of the first and second components, when combined with a portion of the liquid or slurry from the mining process having a pH level of 8 or more, a rapid cross-linking reaction occurs, initiated by the pH level of the liquid or slurry, to form a reaction product intended for use in a mining process fluid stream at one or more locations where solid/liquid separation occurs. The set of chemical additives additionally includes instructions for the use of the first and second compositions in the separation into solid and liquid phases in the mining process. In other embodiments, the polysaccharide is dextran and the boronic acid-containing polymer is a water-soluble polyacrylamide containing boronic acid. In some embodiments of the invention, the mining process is a Bayer process or a process for separating iron ore tailings.

In at least one embodiment, the present invention encompasses a sales kit. The sales kit includes: a first composition containing a polysaccharide and a separate second composition containing a polymer containing boronic acid; and a label with printed instructions on how to use them as a solid-liquid separation additive in a mining process such as the Bayer process. Between the polysaccharide and the polymer containing boronic acid, the first and second components, when combined with a portion of the liquid or slurry from the mining process having a pH level of 8 or more, a rapid cross-linking reaction occurs, initiated by the pH level of the liquid or slurry, to form a reaction product intended for use in a mining process fluid stream at one or more locations where solid/liquid separation occurs. In this and various other embodiments of the invention, the sales kit further includes instructions for use. In other embodiments, the polysaccharide is dextran and the boronic acid-containing polymer is a water-soluble polyacrylamide containing boronic acid.

In at least one embodiment, this invention relates to a method of selling a first composition containing a polysaccharide and a separate second composition containing a polymer containing boronic acid, including packaging of the first and second compositions with labels stating that the compositions are useful as additives for separating solid and liquid phases in a mining process such as the Bayer process. In other embodiments, the polysaccharide is dextran and the boronic acid-containing polymer is a water-soluble polyacrylamide containing boronic acid.

When dextran is crosslinked with a polymer containing boronic acid, there are excellent and unexpected improvements in the performance of the crosslinked material compared to conventionally crosslinked polysaccharides or non-crosslinked counterparts. The use of polysaccharides is constrained by the fact that increasing the doses of polysaccharides in the Bayer fluid results in excellent flocculation only when close to the maximum dose. After reaching the maximum dose, further addition of such polysaccharide material usually does not lead to further improvement in performance.

When using the cross-linked dextran of this invention, excellent performance is achieved. Surprisingly, the maximum performance of the cross-linked dextran of this invention was found to be superior to the maximum performance observed with conventional dextran at any dose.

The methods and compositions disclosed herein are useful for a variety of applications. Such applications include, but are not limited to, aluminum hydroxide flocculation, red mud flocculation, bottom overflow rheology, top overflow cleanliness, settling rate, and filtration rate in the Bayer process; mining applications for iron and lead-zinc ore.

In this and various other embodiments of the invention, the compositions and/or methods described herein may be supplemented or performed in combination with or in accordance with any of the compositions and methods disclosed in US patent No. 8298508 and 8252266 and publication WO 2014158381 , including those related to flocculation and other uses disclosed herein. Also included are patents related to the use of dextran, including US Patent Nos. 6726845, 6740249, 3085853, 5008089, 5041269, 5091159, 5106599, 5346628 and 5716530 and Australian Patent Nos. 5310690 and 737,191. disclosed in the mentioned patents and publications and any others that are otherwise mentioned below or otherwise mentioned in this invention, are incorporated into this document by reference. The prior art described in this document is not intended to enforce the assumption that any patent. publication or other information referred to in this document is "prior art" in relation to this invention, in cases where it is not specifically indicated. Furthermore, it should not be construed as an indication that a study has been performed or that no other significant information exists as defined in 37 CFR 1.56(a).

Examples

The foregoing will be better understood by considering the following examples, which are given for illustrative purposes and are not intended to limit the scope of the invention. In particular, the examples illustrate the typical application of the principles associated with the invention, and these principles are not strictly limited to the specific conditions indicated in these examples. As a result, it should be understood that the invention covers various changes and modifications described herein, and such changes and modifications can be made without departing from the spirit and scope of the invention and without diminishing its intended advantages. Therefore, such changes and modifications are intended to be covered by the appended claims.

A series of studies were conducted on the pH-induced crosslinking reaction and interaction between boronic polymers and dextran, as well as the effect of the crosslinked product in flocculation applications, in accordance with the present invention. Various samples of boron polymers (or "polymer samples") listed in Table 1 were prepared and crosslinked with dextran and compared in various deposition tests, as detailed below. The boronic polymer samples contain APBA as the boronic acid monomer in the amounts shown in Table 1 and contain AM, AA, AA/AM or ATBS as the water soluble vinyl monomer in the amounts shown in Table 1. The polymer sample solutions were nonionic, cationic or anionic.

Cross-linking of boron polymers and dextran occurs rapidly after mixing at pH 8 or higher. Four non-ionic boronic polymers, including samples A, B, C and D, each containing AM as the water-soluble vinyl monomer and having the RSV values shown in Table 1 below, were individually coupled to UHMW dextran ('DX' or 'dextran'). An increase in viscosity was observed for each dextran/boronic polymer solution at pH>10.

Table 1 APBA containing polymers for crosslinking with dextran Samples of boron polymers (SC) Water Soluble Vinyl Monomer APBA% Reduced Specific Viscosity (RSV, dl/g) Sample A (non-ionic) 100% AM 1.0 17.6 Sample B (non-ionic) 100% AM 1.0 14.0 Sample C (non-ionic) 100% AM 1.0 15.4 Sample D (non-ionic) 100% AM 1.8 8.6 Sample E (non-ionic or anionic) 100% AM one 19.3 Sample F (non-ionic or anionic) 8%ATBS one 17.0 Sample G (cationic) 50% cat one 21.8 Sample H
(anionic) 30% AA /
70%AM one 32.5

Deposition test example

Sedimentation tests were also carried out on samples of dextran crosslinked with boron polymers and samples of unmodified dextran to evaluate and compare flocculation characteristics. Samples of dextran crosslinked products with boron polymers in accordance with the present invention were evaluated and compared in programs with commercial polymers. The performance of boron crosslinked dextran as a flocculant for aluminum trihydrate and red mud in the Bayer process and iron ore tailings in iron ore processing slurries was evaluated. Research methods included Aluminum Trihydrate Deposition Cylinder Test; Red mud sedimentation cylinder test; and Test cylinder for iron ore tailings settling. The protocols for these test methods were as follows:

Aluminum Trihydrate Deposition Cylinder Test:

In the cylinder test, 200 ml bottles of waste Bayer fluid (Bayer process fluid with a total caustic content of Na ₂ CO ₃ 233.6 g/L) were collected and stored in a water bath at 60 °C. For the test sample, the bottle was removed from the water bath and 10 g of fine aluminum trihydrate seeds (standard aluminum trihydrate seeds supplied by RJ Marshall Co, USA) (50 g/L aluminum trihydrate solids) were added to the liquid. Then, to suspend the hydrate solids, the bottle was shaken for 30 seconds, and then a given volume of flocculant solution containing samples of the flocculant was introduced. The bottle was then manually agitated for 1 min to bring the flocculant sample into contact with the solids. The resulting suspension was then transferred to a 250 ml graduated cylinder. The amount of solids in the top drain for each sample was determined after 3 sedimentations by collecting 60 ml of the supernatant at the top of the cylinder and filtering it through glass fiber filter paper.

Red mud sedimentation cylinder test:

In the cylinder test, 1000 ml of a slurry from the Bayer process containing red mud was placed in the cylinder. For a given test sample, a predetermined volume of solution containing the flocculant sample was added to the slurry and then agitated to bring the flocculant into contact with the solids. After stopping the stirring, a timer was started. At a given time ʺtʺ, the position of the interface was recorded to estimate the hydrate settling rate.

Iron ore tailing cylinder test:

In the cylinder test, 1000 ml of a slurry from the Bayer process containing iron ore tailings was placed in a cylinder. For a given test sample, a predetermined volume of solution containing the flocculant sample was added to the slurry and then agitated to bring the flocculant into contact with the solids. After stopping the stirring, a timer was started. At a given time ʺtʺ, the position of the interface was recorded to estimate the rate of hydrate settling.

Sample test:

Example 1:

A cylinder test for deposition of aluminum trihydrate was performed with aluminum trihydrate in a Bayer fluid. Samples A1, B1, C1 and D1 were tested and compared with dextran (DX sample) (UHMW dextran), HyClass flocculant (HC sample) supplied by Nalco Company of Naperville, Ill., and blank. Samples A1, B1, C1 and D1 are the crosslinking reaction products of dextran and each of samples A, B, C and D, respectively. FIG. 1 shows the percent reduction in solids in the overflow when equal doses of samples (DX, A1, B1, C1, D1 and HC) are added. The active dextran level was 3.25 ppm.

As shown in FIG. 1 unexpectedly found that the performance after crosslinking was significantly improved compared to uncrosslinked dextran. Even more surprisingly, sample A1, which is dextran crosslinked to sample A, which has the highest RSV of samples A-D, performed similarly to the commercial product. This is significant, at least in terms of efficiency, due to the significant reduction in the crosslinking time required for samples A1-D1, which is, in some embodiments of the invention, 1-30 minutes, i.e., much less compared to commercial products. , in which it is 1-20 hours.

Example 2:

A cylinder test for aluminum trihydrate precipitation was conducted to demonstrate the effect of the percentage of boron polymer introduced on crosslinked dextran performance in aluminum trihydrate flocculation. Two samples (A2A, A2B) were matched with dextran (sample DX). Samples A2A and A2B are dextran crosslinked to sample A. Samples of boronic polymer crosslinked dextran (A2A, A2B) were made with different ratios of boronic polymer to dextran. Sample A2B had a higher ratio (6% boronic polymer) than sample A2A (0.6% boronic polymer). Waste Bayer fluid was used as the process fluid, and aluminum trihydrate seed grains were used as the flocculant carrier.

As shown in FIG. 2, the cross-linked dextran with a higher percentage of boron polymer incorporation (Sample A2B) was superior to the cross-linked dextran (Sample A2A) with a lower percentage of boron polymer incorporation.

Example 3:

A red mud sedimentation cylinder test was conducted to demonstrate the effectiveness of boron polymers in flocculating red mud (Bayer process red mud). Prepared and tested three samples (E3, F3) of dextran cross-linked with non-ionic or anionic boron polymers, samples E and F, respectively. During testing, cross-linked dextran (samples E3 and F3) was co-administered with conventional red mud flocculant (RF). FIG. 3, the x-axis (XLD ppm) indicates the level of addition (increased doses) of dextran crosslinked to boron polymer samples E3 and F3 in ppm. "0" at the left end of the x-axis indicates the introduction of conventional red mud flocculant (RF) alone. Co-administration of conventional flocculant (RF) was carried out at constant concentrations.

As shown in FIG. 3, compared with the addition of conventional red mud flocculant alone (x=0), when it was co-administered with cross-linked dextran, a significant improvement in settling rate was observed (from 6.1 m/h to 12.2 m/h (from 20 ft/h). hour to 40 ft/hour)).

Example 4:

An iron ore tailing cylinder test was conducted to demonstrate the effectiveness of boron polymers when used to flocculate iron ore tailings. Sedimentation tests were carried out in iron ore tailings slurry comparing the co-injection of a conventional flocculant (CF) with dextran cross-linked with boronic polymers (G4) and the co-injection of the same conventional flocculant (CF) with a conventional coagulant (CC). The conventional flocculant (CF) was Optimer® 83949 flocculant, which is an anionic flocculant and is available from Nalco Company of Naperville, Ill.; the conventional coagulant (CC) was cationic coagulant CAT-FLOC 8799 PLUS, which is supplied by the Nalco Company of Naperville, Ill.; and dextran cross-linked with boron polymers (G4) was a sample of dextran (DX) cross-linked with a sample of boron polymer G (see Table 1). Conventional flocculant (CF) was injected at a constant concentration, and G4 and CC were each applied and measured at various doses as shown in ppm units. on the x-axis (polymer cat, ppm).

As shown in FIG. 4, co-injection of dextran (G4) cross-linked with cationic boron polymer and conventional anionic flocculant (CF) shows a significant improvement in performance (higher settling rate) in iron ore tailings flocculation compared to conventional co-introduction of conventional cationic coagulant (CC) and conventional anionic flocculant (CF).

As shown in Examples 1-4 above, in mining deposition applications, significant performance improvements are observed when dextran is cross-linked with boronic polymers as proposed herein. The characteristics, combined with the in situ and rapid reaction advantages of the methods and compositions of this invention, provide significant advantages over conventional flocculation processes. The effectiveness and productivity of the methods and compositions disclosed herein provide cost savings and an equal or improved rate of optimized dosage.

Although the invention may be embodied in many different forms, specific embodiments of the invention are illustrated in the drawings and described in detail herein. This disclosure is illustrative of the basic principles of the invention and is not intended to limit the invention to the particular illustrated embodiments. All patents, patent publications, scientific papers, and any other materials mentioned anywhere in this document are incorporated herein by reference in their entirety for all purposes, including the provision of materials, formulations, methods of formulation, and methods of manufacture, performance, and use, insofar as they relate to the methods and compositions of this invention. In addition, the invention covers all possible combinations of some or all of the various embodiments described herein and introduced herein.

The above disclosure is illustrative and not exhaustive. This description presents many variations and alternatives to those skilled in the art. All of these alternatives and variations are intended to be included within the scope of the claims, where the term "including" means "including, but not limited to". Those skilled in the art will see other equivalents to the specific embodiments of the invention described herein, and these equivalents are also covered by the claims.

References to "embodiment(s)", "disclosure", "this disclosure", "embodiment(s) of the disclosure", "disclosed embodiment(s)", etc., which are contained in this document, refer to the specification (text, including the Claims and Figures ) of this patent application, which is not a recognized state of the art.

All ranges and parameters disclosed herein should be taken to encompass any and all subranges included therein and every number between the endpoints. For example, a stated range of "1 to 10" should be considered to include any and all sub-ranges between (and including) a minimum value of 1 and a maximum value of 10; in other words, all subranges ranging from a minimum value of 1 or more, (for example, from 1 to 6.1), and ending with a maximum value of 10 or less, (for example, from 2.3 to 9.4, from 3 to 8, 4 to 7) and finally every number 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 contained within the range.

Various embodiments of the present invention have been described. However, it should be understood that various modifications can be made without departing from the spirit and scope of the invention. Those skilled in the art will see other equivalents to the specific embodiments of the invention described herein, and these equivalents are also covered by the appended claims. For the purposes of interpreting the Claims of the present invention, it is expressly stated that the provisions of Section 112, sixth paragraph of 35 U.S.C. should not be used unless the specific terms "intended for" or "aimed at" are mentioned in the Claims.

Claims (42)

1. A method for separating a solid-liquid in a mining process liquid stream having a pH of 8 or more, comprising the following steps in the following order: combining a polymer containing boronic acid with said liquid stream; combining the polysaccharide with said fluid stream; and separating the solid from said liquid stream. 2. The method according to claim 1, characterized in that said boronic acid-containing polymer contains acrylamide. 3. The method of claim 1, wherein said boronic acid-containing polymer has a reduced specific viscosity of at least about 0.2 dl/g. 4. The method according to claim 1, characterized in that said polymer containing boronic acid is in the form of a latex, an aqueous solution or a dry powder. 5. The method of claim 1, wherein said fluid stream is a Bayer fluid stream and the reaction product of the polysaccharide with a polymer containing boronic acid inhibits the rate of nucleation of one or more alumina trihydrate crystals in the Bayer fluid stream. 6. The method of claim 1, wherein said fluid stream is a Bayer fluid stream and the reaction product of a polysaccharide with a polymer containing boronic acid facilitates the cleanup of red mud in the Bayer fluid stream. 7. A method for separating a solid-liquid in a mining process liquid stream having a pH of 8 or more, comprising the following steps in the following order: combining the polysaccharide with said fluid stream; combining a polymer containing boronic acid with said liquid stream; and separating the solid from said liquid stream. 8. Method according to claim 7, characterized in that said boronic acid-containing polymer contains acrylamide. 9. The method of claim 7, wherein said boronic acid-containing polymer has a reduced specific viscosity of at least about 0.2 dl/g. 10. The method according to claim 7, characterized in that said polymer containing boronic acid is in the form of a latex, an aqueous solution or a dry powder. 11. The method of claim 7 wherein said association of the polysaccharide with the boronic acid containing polymer inhibits the rate of nucleation of one or more alumina trihydrate crystals in the Bayer process. 12. The method according to claim 7, characterized in that the reaction product of the polysaccharide with a polymer containing boronic acid facilitates the purification of red mud in the Bayer process. 13. A method for solid-liquid separation in a mining process liquid stream having a pH of 8 or more, comprising: simultaneous association of the first component and the second component with the specified liquid stream, while the specified first component contains a polymer containing boronic acid, the specified second component contains a polysaccharide; and separating the solid from said liquid stream. 14. The method of claim 13, wherein said boronic acid-containing polymer contains acrylamide. 15. The method of claim 13, wherein said boronic acid-containing polymer has a reduced specific viscosity of at least about 0.2 dl/g. 16. The method according to claim 13, characterized in that said boronic acid-containing polymer is in the form of a latex, an aqueous solution or a dry powder. 17. The method of claim 13 wherein the reaction product of the polysaccharide with the boronic acid containing polymer inhibits the rate of nucleation of one or more alumina trihydrate crystals in the Bayer process. 18. The method according to claim 13, characterized in that the reaction product of the polysaccharide with a polymer containing boronic acid facilitates the purification of red mud in the Bayer process. 19. A method for solid-liquid separation in a mining process liquid stream having a pH of 8 or more, comprising mixing a polymer containing boronic acid with a polysaccharide to form an unreacted mixture, adding the unreacted mixture to said liquid stream to form a reaction product of a polymer containing boronic acid and a polysaccharide; and separating the solid from said liquid stream. 20. The method according to claim 19, characterized in that said unreacted mixture is a solution. 21. The method according to claim 19 or 20, characterized in that said mining process is a Bayer process. 22. The method of claim 21, wherein said separation is the nucleation of one or more alumina trihydrate crystals. 23. The method according to claim 21, characterized in that said separation is a purification of red mud in the Bayer process. 24. The method according to claim 19 or 20, wherein the mining process is a process for separating iron ore tailings. 25. The method according to claim 24, characterized in that said separation is a separation of iron ore tailings. 26. A set of components for adding to a liquid stream of a mining process, having a pH of 8 or more, containing dextran; and boronic acid-containing polymer containing acrylamide and a vinyl monomer containing a boronic acid moiety selected from the group consisting of 3-(acrylamido)phenylboronic acid, 4-(acrylamido)phenylboronic acid, 2-(acrylamide)phenylboronic acid, 4-vinylphenylboronic acid acid, 3-vinylphenylboronic acid, 2-vinylphenylboronic acid and mixtures thereof. 27. The kit according to claim 26, characterized in that the polymer containing boronic acid further comprises a monomer selected from the group consisting of acrylic acid or its salt, 2-acrylamido-2-methylpropane sulfonic acid or its salt, N,N ,N-trimethyl-2-[(1-oxo-2-propenyl)oxy]-ethanaminium chloride or N,N-dimethyl-N-propenyl-2-propene-l-aminium chloride. 28. The set according to claim 26, characterized in that the polymer containing boronic acid and dextran are provided for addition to the specified liquid stream in a ratio of 0.01% wt. up to 50% wt. polymer containing boronic acid, and the rest - dextran. 29. Set according to claim 26, characterized in that the polymer containing boronic acid contains from 0.5% wt. up to 2.5% wt. 3-(acrylamido)phenylboronic acid, 4-(acrylamido)phenylboronic acid, 2-(acrylamide)phenylboronic acid, 4-vinylphenylboronic acid, 3-vinylphenylboronic acid, 2-vinylphenylboronic acid, or mixtures thereof.

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