CN102066544A - A spray-drying process - Google Patents

Abstract

The present invention relates to a process for preparing a spray-dried powder comprising (i) anionic detersive surfactant; (ii) from 0wt% to 10wt% zeolite builder; (iii) from 0wt% to 10wt% phosphate builder; and (iv) optionally from 0wt% to 15wt% silicate salt; wherein the process comprises the steps of: (a) forming an alkaline slurry in a mixer, the slurry comprising: (v) from 0wt% to 15wt% anionic detersive surfactant; (vi) from 0wt% to 35wt% water; and (b) transferring the alkaline slurry from the mixer through at least one pump to a spray pressure nozzle; (c) contacting an acid anionic detersive surfactant precursor to the alkaline slurry after the mixer and before the spray pressure nozzle to form a mixture; (d) spraying the mixture through the spray pressure nozzle into a spray-drying tower; (e) spray-drying the mixture to form a spray-dried powder; and (f) optionally, contacting an alkalinity source with the alkaline slurry and/or the acid anionic detersive surfactant precursor, and/or the mixture.

Description

spray drying method

field of invention

The present invention relates to spray drying methods.

Background of the invention

Laundry detergent compositions are typically made by a process involving the step of spray drying an aqueous slurry comprising an anionic detersive surfactant to form a spray dried powder. Typically, this spray drying step is the rate determining step for making laundry detergent powders. This is especially true for low formulated formulations with increased dry loading. With the global demand for laundry detergent powder volumes increasing, many detergent manufacturers are operating their spray drying towers at or near maximum capacity. To increase the throughput of their existing spray drying equipment, detergent manufacturers have had to invest in additional or upgrade spray drying equipment, and/or formulate their spray dried powders with processing aids, which increase the spray Formulation Complexity of Dry Laundry Detergent Powders.

The inventors have found that by removing at least a portion of the anionic detersive surfactant from the aqueous slurry in the mixer and adding its acidic precursor (i.e. to the alkaline slurry) at a later stage in the spray drying process, and By carefully controlling the moisture content of the alkaline slurry in the mixer, the throughput of the spray drying process can be significantly increased without the need to invest in additional spray drying equipment or incorporate processing aids.

Summary of the invention

The present invention relates to a method as defined in claim 1 .

Detailed description of the invention

spray drying method

The method comprises the steps of: (a) forming an alkaline slurry in an agitator; (b) transferring, by at least one pump, the alkaline slurry from the agitator to a spray pressurized nozzle; (c) while agitating contacting an acidic anionic detersive surfactant precursor with the alkaline slurry to form a mixture after the sprayer and before the spray pressurization nozzle; (d) spraying the mixture through the spray pressurization nozzle into a spray drying tower wherein; (e) spray drying said mixture to form a spray dried powder; and (f) optionally, combining a source of alkalinity with said alkaline slurry and/or said acidic anionic detersive surfactant precursor and / or the mixture is contacted. Each procedure is described in more detail below.

step (a)

In step (a), an alkaline slurry is formed in a mixer. The preferred agitator in step (a) is a helical agitator. It is generally preferred to heat the alkaline slurry in the agitator in the range of 50°C to 90°C. Saturated steam can be used to heat the slurry in the mixer. All liquid components making up the slurry are preferably heated before being added to the mixer, and the slurry is preferably maintained at an elevated temperature in the mixer. These temperatures are preferably in the range of 50°C to 90°C.

The residence time of the slurry in the mixer typically ranges from 20 seconds to 600 seconds.

The stirrer in step (a) usually has a certain motor power, so that its installed power is in the range of 50kW to 100kW.

step (b)

In step (b), the alkaline slurry is transferred from the mixer to the spray pressurized nozzle by at least one pump. Usually the alkaline slurry is first transferred to a low pressure line. The subline typically has a pressure in the range of 4.0×10 ⁵ Pa to 1.2×10 ⁶ Pa. Typically the alkaline slurry is then pumped into a high pressure line. High pressure lines typically have a pressure in the range of 4.0×10 ⁶ Pa to 1.2×10 ⁷ Pa. Typically, a high pressure pump is used to transfer the alkaline slurry from a low pressure line to a high pressure line. The high pressure pump is preferably a piston pump.

Typically, during step (b), the alkaline slurry is passed through the second agitator. The second agitator is preferably a slurry breaker. The second agitator typically operates at a rate of 1,000 rpm to 3,000 rpm. This second agitator reduces the particle size of the solid matter in the slurry. The particle size of the solid matter in the slurry at the end of step (b) is preferably less than 2.0 mm. This reduces the risk of clogging the spray pressurized nozzles.

step (c)

In step (c), after the agitator and before the spray pressurized nozzle, the acidic anionic detersive surfactant precursor is contacted with the basic slurry to form a mixture. The acidic anionic surfactant precursor is contacted with the alkaline slurry, preferably in a low pressure line. However, it is possible to contact the acidic anionic surfactant precursor with the alkaline slurry in a high pressure line. The temperature of the acidic anionic detersive surfactant precursor is typically in the range 20°C to 50°C when it is contacted with the alkaline slurry. Typically the ratio of basic slurry flow to acidic anionic detersive surfactant precursor flow is controlled. This control is usually accomplished by passing the acidic anionic detersive surfactant precursor through a mass flow meter and monitoring the mass flow of the alkaline slurry, which is typically pumped is delivered to the storage tank before going to the low pressure line. The ratio of alkaline slurry flow to acidic anionic detersive surfactant precursor flow is generally in the range of 2.5:1 to 25:1, preferably 5:1, or 8:1, and preferably to 20:1, or to 15:1 within range.

step (d)

In step (d), the mixture is sprayed through spray pressurized nozzles into a spray drying tower. The mixture is usually sprayed at a pressure ranging from 4.0×10 ⁶ Pa to 1.2×10 ⁷ Pa. The mixture is typically sprayed at a mass flow rate in the range of 1,000 kghr ⁻¹ to 70,000 kghr ⁻¹ . Usually a plurality of nozzles are used in the process, which nozzles are preferably arranged in a circumferential manner at different heights throughout the spray-drying tower. The nozzles are preferably positioned relatively countercurrent to the gas flow in the column.

step (e)

In step (e), the mixture is spray dried to form a spray dried powder. The inlet temperature is typically in the range of 200°C to 350°C. Inlet flow is typically in the range of 50,000 to 150,000kgm ^-3 .

Optional step (f)

In optional step (f), the source of alkalinity is contacted with the alkaline slurry and/or the acidic anionic detersive surfactant precursor and/or said mixture. Preferably, the source of alkalinity is added to the alkaline slurry substantially simultaneously with the acidic anionic detersive surfactant precursor. The source of alkalinity is contacted with the alkaline slurry and/or acidic anionic detersive surfactant precursor and/or mixture, typically at a temperature above 10°C; this is especially preferred when the source of alkalinity comprises sodium hydroxide .

The source of alkalinity may be contacted with the alkaline slurry and/or mixture by injecting the source into a low pressure line. Alternatively, a source of alkalinity can be injected into the high pressure line.

Typically the ratio of alkaline slurry flow to alkalinity source flow is controlled. This control is usually accomplished by passing the source of alkalinity through a mass flow meter. Control of alkaline slurry mass flow is described in more detail above.

alkaline slurry

The alkaline slurry typically comprises: (a) 0% to 15% by weight anionic detersive surfactant; and (b) 0% to 35% by weight water. The alkaline slurry preferably comprises 0% by weight, or more than 0% by weight, and preferably to 30% by weight, or to 25% by weight, or to 20% by weight, or to 15% by weight, or even to 10% by weight of water . The alkaline slurry may be substantially anhydrous. The alkaline slurry typically contains one or more detergent builder ingredients. The alkaline slurry preferably comprises carbonate, preferably at least 5% by weight, or at least 10% by weight of carbonate. The alkaline slurry preferably comprises 0% to 10% by weight, or more than 0% by weight, and preferably to 8% by weight, or to 6% by weight, or to 2% by weight of anionic surfactant. The alkaline slurry may even be substantially free of anionic detersive surfactants. Substantially free generally means free of intentional additions.

The alkaline slurry may contain polymeric material. Preferred polymeric materials are carboxylate polymers. The alkaline slurry may comprise at least 1% by weight, or even at least 2% by weight of polymeric material.

The weight ratio of solid inorganic material to solid organic material present in the slurry is preferably in the range of 10:1 to 10,000:1, preferably at least 35:1. The alkaline slurry may contain less than 10% by weight solid organic material, or less than 5% by weight solid organic material. The alkaline slurry may even be substantially free of solid organic material. For the purposes of the present invention, organic means any hydrocarbon component.

spray dried powder

The spray dried powder comprises: (i) an anionic detersive surfactant; (ii) 0% to 10% by weight zeolite builder; (iii) 0% to 10% by weight phosphate builder and (iv) optionally 0% to 15% by weight silicate. The spray-dried powders generally contain additional detergent builder ingredients. The spray-dried powder preferably comprises carbonate.

The spray-dried powder generally has a particle size distribution such that the weight average particle size is in the range of 300 microns to 600 microns, and preferably less than 10% by weight of the spray-dried powder has a particle size greater than 1,180 microns, and preferably less than 10% by weight The spray-dried powder has a particle size of less than 150 microns.

The spray-dried powder typically has a bulk density in the range of 100 g/L to 700 g/L. The spray-dried powder typically has a moisture content of less than 5%, preferably less than 4%, or even less than 3% by weight. The spray-dried powder is preferably white.

Acidic anionic detersive surfactant precursor

The acidic anionic detersive surfactant precursor preferably comprises a C ₈ -C ₂₄ alkylbenzene sulfonic acid. However, any acidic anionic detersive surfactant precursor can be used in the present invention.

Anionic detersive surfactants

提供的那些，或由Petresa以商品名提供的那些，其它适宜的LAB包括高级2-苯基LAB，如由Sasol以商品名提供的那些。Anionic detersive surfactants preferably comprise alkylbenzene sulphonates. The anionic detersive surfactant preferably comprises at least 50%, preferably at least 55%, or at least 60%, or at least 65%, or at least 70%, or even at least 75% by weight of the anionic detersive surfactant % of alkylbenzene sulfonates. The alkylbenzene sulfonate is preferably linear or branched, substituted or unsubstituted C _8-18 alkylbenzene sulfonate. This is the optimum content of C _8-18 alkylbenzene sulfonate to provide good cleaning performance. C _8-18 alkylbenzene sulfonate can be modified alkylbenzene sulfonate (MLAS), such as WO 99/05243, WO 99/05242, WO 99/05244, WO 99/05082, WO 99/05084, WO 99/05241, WO 99/07656, WO 00/23549 and WO 00/23548 are described in more detail. Highly preferred C _8-18 alkylbenzene sulfonates are linear C _10-13 alkylbenzene sulfonates. Especially preferred are linear C _10-13 alkylbenzene sulfonates obtainable, preferably by sulfonation, of commercially available linear alkylbenzenes (LAB); suitable LABs include lower 2-phenyl LAB, As marketed by Sasol under the trade name

those offered, or by Petresa under the tradename Those provided, other suitable LABs include higher 2-phenyl LABs such as those available from Sasol under the tradename those provided.

The anionic detersive surfactants may preferably comprise other anionic detersive surfactants. Preferred anionic detersive surfactant builders are non-alkoxylated anionic detersive surfactants. The non-alkoxylated anionic detersive surfactant may be an alkyl sulfate, alkyl phosphate, alkyl phosphonate, alkyl carboxylate, or any mixture thereof. Non-alkoxylated anionic surfactants may be selected from the group consisting of C ₁₀ -C ₂₀ branched, linear and random chain primary alkyl sulfates (AS) generally having the structure:

CH ₃ (CH ₂ ) _x CH ₂ -OSO ₃ ^- M ⁺

Wherein, M is hydrogen or a cation providing electrical neutrality, preferred cations are sodium and ammonium cations, wherein x is an integer of at least 7, preferably at least 9; typical C ₁₀ -C ₁₈ secondary (2, 3) Alkyl Sulfate:

Wherein, M is hydrogen or a cation providing electrical neutrality, preferred cations include sodium and ammonium cations, wherein x is an integer of at least 7, preferably at least 9, and y is an integer of at least 8, preferably at least 9; C ₁₀ -C ₁₈ Alkyl carboxylates; mid-chain branched alkyl sulfates, as described in more detail in US 6,020,303 and US 6,060,443; methyl ester sulfonate (MES); alpha-olefin sulfonate (AOS); mixture.

Another preferred anionic detersive surfactant is an alkoxylated anionic detersive surfactant. The presence of the alkoxylated anionic detersive surfactant in the spray-dried powder provides good oily stain cleaning performance, imparts good sudsing characteristics, and improves the hardness tolerance of the anionic detersive surfactant system. The anionic detersive surfactant system preferably comprises from 1% to 50%, or 5%, or 10%, or 15%, or 20%, and to 45%, by weight of the anionic surfactant system, or To 40%, or to 35%, or to 30% alkoxylated anionic detersive surfactant.

Preferably, the alkoxylated anionic detersive surfactant is a linear or branched, substituted or unsubstituted C _12-18 alkyl alkoxylated sulfate having an average alkoxy The degree is 1 to 30, preferably 1 to 10. Preferably, the alkoxylated anionic detersive surfactant is a linear or branched, substituted or unsubstituted C _12-18 alkyl ethoxylate sulfate having an average Ethoxylate of 1 to 10 Oxylation degree. Most preferably, the alkoxylated anionic detersive surfactant is a linear unsubstituted C _12-18 alkyl ethoxylate sulfate having an average degree of ethoxylation of 3 to 7.

When present together with alkylbenzene sulfonates, alkoxylated anionic detersive surfactants can also increase the Activity of alkylbenzene sulfonates. The weight ratio of alkylbenzene sulfonate to alkoxylated anionic detersive surfactant is preferably from 1:1 to less than 5:1, or to less than 3:1, or to less than 1.7:1, or even less than 1.5:1 1 range. This ratio gives the best whiteness retention performance combined with good hardness tolerance characteristics and good lather characteristics. However, the weight ratio of alkylbenzene sulfonate to alkoxylated anionic detersive surfactant is preferably greater than 5:1, or greater than 6:1, or greater than 7:1, or even greater than 10:1. This ratio gives the best oil cleaning performance in combination with good hardness tolerance characteristics and good foaming characteristics.

Suitable alkoxylated anionic detersive surfactants are: TexapanLEST ^™ from Cognis; Cosmacol AES ^™ from Sasol; BES151 ^™ from Stephan; Empicol ESC70/U ^™ ;

The anionic detersive surfactant preferably comprises from 0% to 10%, preferably to 8%, or to 6%, or to 4%, or to 2%, or even by weight of the anionic detersive surfactant to 1% of unsaturated anionic detersive surfactants such as alpha-olefin sulfonates. The anionic detersive surfactants are preferably substantially free of unsaturated anionic detersive surfactants such as alpha-olefin sulfonates. "Essentially free" typically means "free of intentionally added". Without wishing to be bound by theory, it is believed that this level of unsaturated anionic detersive surfactant, such as alpha-olefin sulfonate, ensures that the anionic detersive surfactant is bleach compatible.

The anionic detersive surfactant preferably comprises from 0% to 10% by weight, preferably to 8% by weight, or to 6% by weight, or to 4% by weight, or to 2% by weight, or even to 1% by weight of alkanes base sulfate. The anionic detersive surfactants are preferably substantially free of alkyl sulfates. While wishing to be bound by theory, it is believed that this level of alkyl sulfate ensures that the anionic detersive surfactant is hardness resistant.

Zeolite Builder

The spray-dried powder generally comprises 0% to 10% by weight, preferably to 9% by weight, or to 8% by weight, or to 7% by weight, or to 6% by weight, by weight of the spray-dried powder, Or to 5 wt%, or to 4 wt%, or to 3 wt%, or to 2 wt%, or to 1 wt%, or to less than 1 wt% zeolite builder. The spray-dried powder may even preferably be substantially free of zeolite builder. Substantially free of zeolite builder generally means that the spray-dried powder contains no intentionally added zeolite builder. If it is desired that the spray-dried powder is very soluble, it is especially preferred to minimize the amount of water-insoluble residue (which can deposit on fabric surfaces, for example), and also when a clear wash liquor is highly desired. Zeolite builders include zeolite A, zeolite X, zeolite P and zeolite MAP.

Phosphate Builder

The spray-dried powder generally comprises 0% to 10% by weight, preferably to 9% by weight, or to 8% by weight, or to 7% by weight, or to 6% by weight, by weight of the spray-dried powder, Or to 5 wt%, or to 4 wt%, or to 3 wt%, or to 2 wt%, or to 1 wt%, or to less than 1 wt% phosphate builder. The spray dried powder may even preferably be substantially free of phosphate builders. Substantially free of phosphate builder generally means that the spray-dried powder contains no intentionally added phosphate builder. This is especially preferred if the composition is desired to have very good environmental properties. Phosphate builders include sodium tripolyphosphate.

Silicate

The spray-dried powder optionally comprises 0% to 20% by weight, preferably 1% by weight, or 2% by weight, or 3% by weight, and preferably to 15% by weight, or to 10% by weight, or even to 5% by weight % silicate. Silicates include amorphous silicates and crystalline layered silicates (eg SKS-6). A preferred silicate is sodium silicate.

carbonate

The spray-dried powder typically comprises carbonate, typically from 1% to 50%, or from 5% to 25%, or from 10% to 20%, by weight of the spray-dried powder. Preferred carbonates are sodium carbonate and/or sodium bicarbonate. A highly preferred carbonate is sodium carbonate. The spray-dried powder may preferably comprise 10% to 40% sodium carbonate by weight of the spray-dried powder. However, the spray-dried powder may also preferably comprise from 2% to 8% by weight of the spray-dried powder of sodium bicarbonate. This level of sodium bicarbonate provides good alkalinity while minimizing the possibility of surfactant gelling that can occur in surfactant-carbonate systems. If the spray-dried powder comprises sodium carbonate and zeolite, the weight ratio of sodium carbonate to zeolite is preferably at least 15:1.

A high level of carbonate improves the cleaning performance of the composition by increasing the pH of the wash liquor. This increased alkalinity: improves bleach performance, if present; increases the hydrolysis propensity of soils, which facilitates their removal from fabrics; and also increases the rate and extent of ionization of the soils to be cleaned (note, During the wash phase, the ionized soil is more soluble and easier to remove from the fabric). Furthermore, the high carbonate content increases the flowability of the spray-dried powder.

Alkalinity source

The source of alkalinity preferably comprises sodium hydroxide. The source of alkalinity preferably comprises carbonates. The source of alkalinity preferably comprises a silicate.

detergent builder ingredients

Suitable adjunct ingredients include: detersive surfactants such as anionic detersive surfactants, nonionic detersive surfactants, cationic detersive surfactants, zwitterionic detersive surfactants, amphoteric detersive surfactants; Preferred nonionic detersive surfactants are _C8-18 alkyl alkoxylated alcohols having an average degree of alkoxylation of 1 to 20, preferably 3 to 10, most preferably an average degree of alkoxylation of 3 C _12-18 alkyl ethoxylated alcohols to 10; preferred cationic detersive surfactant is mono-C _6-18 alkyl monohydroxyethyl dimethyl quaternary ammonium chloride, more preferably mono- C _8-10 alkyl one-hydroxyethyl dimethyl quaternary ammonium chloride, one-C _10-12 alkyl one-hydroxyethyl dimethyl quaternary ammonium chloride, and one-C ₁₀ alkyl one-hydroxy Ethyldimethyl quaternary ammonium chloride; peroxygen source such as percarbonate and/or perborate, preferably sodium percarbonate, peroxygen source is preferably at least partially coated with the coating composition, preferably completely coated with the composition Coatings, said coating ingredients such as carbonates, sulfates, silicates, borosilicates, or mixtures thereof, including mixed salts thereof; bleach activators such as tetraacetylethylenediamine, phenolsulfonic acid Salt bleach activators such as nonanoylphenol sulfonate, caprolactam bleach activators, imide bleach activators such as N-nonanoyl-N-methylacetamide, preformed peracids such as N,N-phthalamide Acylated aminoperoxycaproic acid, nonylamide peroxyadipate, or dibenzoyl peroxide; enzymes such as amylases, carbohydrases, cellulases, laccases, lipases, oxidases, peroxidases , proteases, pectate lyases and mannanases; suds suppressor systems such as silicone-based suds suppressors; optical brighteners; photobleaches; salt fillers such as sulfates, preferably sodium sulfate; fabric softeners such as clays, silicones and/or quaternary ammonium compounds; flocculants such as polyethylene oxide; dye transfer inhibitors such as polyvinylpyrrolidone, poly-4-vinylpyridine N-oxide and/or vinylpyrrolidone and vinyl Copolymers of imidazole; textile integral components such as hydrophobically modified cellulose and oligomeric products of condensation of imidazole and epichlorohydrin; soil dispersants and soil anti-redeposition aids such as alkoxylated polyamines and ethoxylated ethyleneimine polymer; anti-redeposition components such as carboxymethylcellulose and polyester; perfume; sulfamic acid or its salt; citric acid or its salt; and dyes such as orange dye, blue dye , green dye, purple dye, pink dye, or mixtures thereof.

Example

While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the appended claims are intended to cover all such changes and modifications that are within the scope of this invention.

Example 1: Spray dried laundry detergent powder and method of making it.

Aqueous alkaline slurry compositions .

component Aqueous Serum (number of parts) Sodium silicate 8.5 Acrylate/Maleate Copolymer 3.2 Hydroxyethane bis(methylene phosphonic acid) 0.6 Sodium carbonate 8.8

sodium sulfate 42.9 water 19.7 Miscellaneous such as magnesium sulfate, and one or more stabilizers 1.7 Parts of aqueous alkaline serum 85.4

Preparation of spray dried laundry detergent powder .

In a slurry maker vessel (screw mixer), an aqueous alkaline slurry was prepared with the composition as described above. The water content of the above slurry was 23.1%. Any ingredients added above in liquid form are heated to 70°C such that the temperature of the aqueous slurry never falls below 70°C. Saturated steam was injected into the helical stirrer at a pressure of 6.0×10 ⁵ Pa to raise the temperature to 90°C. The slurry was then pumped into the low pressure line (with a pressure of 5.0 x ¹⁰⁵ Pa).

11.4 parts of C ₈ -C ₂₄ alkylbenzene sulfonic acids (HLAS) and 3.2 parts of 50 wt/w% aqueous sodium hydroxide solution were pumped into the low pressure line, respectively. The mixture was then pumped into a high pressure line (with an outlet pressure of 8.0×10 ⁶ Pa) via a high pressure pump. Then, at a pressure of 8.0×10 ⁶ Pa and a temperature of 90°C+/−2°C, the mixture was sprayed through a spray pressurized nozzle at a rate of 1,640 kg/h into a countercurrent spray drying tower with a gas inlet temperature of 300°C. The mixture was atomized and the atomized slurry was dried to produce a solid mixture which was then cooled and sieved to remove oversized material (>1.8 mm) to form a free-flowing spray-dried powder. The fine material (<0.15mm) is washed with the exhaust gas in the spray drying tower, and then collected in the anti-leakage system behind the tower. The spray-dried powder had a moisture content of 2.5% by weight, a bulk density of 510 g/L and a particle size distribution such that greater than 80% by weight of the spray-dried powder had a particle size of 150 to 710 microns. The composition of the spray-dried powder is given below.

Spray-dried laundry detergent powder composition

component % by weight of spray-dried powder (%w/w) Sodium silicate 10.0 C ₈ -C ₂₄ alkylbenzene sulfonate 15.1 Acrylate/Maleate Copolymer 4.0 Hydroxyethane bis(methylene phosphonic acid) 0.7 Sodium carbonate 11.9 sodium sulfate 53.7 water 2.5

Miscellaneous such as magnesium sulfate, and one or more stabilizers 2.1 total number of copies 100.00

Granular laundry detergent composition

The above laundry detergent compositions were prepared by dry blending all of the above granules (all granules except AE7) in a standard batch mixer. AE7 in liquid form was sprayed onto the granules in a standard batch mixer. Alternatively, AE7 in liquid form was sprayed onto the spray-dried powder of Example 1. The resulting powder was then blended together with all other granules in a standard batch mixer.

The dimensions and values disclosed herein are not intended to be understood as strictly limited to the precise values recited. Instead, unless otherwise indicated, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."

Claims (8)

1. method for preparing spray-dired powder, described powder comprises

(i) anionic detersive surfactant;

The (ii) zeolite builders of 0 weight % to 10 weight %;

The (iii) phosphate builders of 0 weight % to 10 weight %; With

The (iv) silicate of Ren Xuan 0 weight % to 15 weight %;

Wherein said method may further comprise the steps:

(a) form alkaline slurry in agitator, described slurries comprise:

(the v) anionic detersive surfactant of 0 weight % to 15 weight %;

(the vi) water of 0 weight % to 35 weight %; And

(b) make described alkaline slurry be transferred to the spraying pressurized nozzles by at least one pump from described agitator;

(c) after described agitator and before described spraying pressurized nozzles, acidic anionic detersive surfactant precursor is contacted to form mixture with described alkaline slurry;

(d) described mixture is sprayed in the spray-drying tower by described spraying pressurized nozzles;

(e) the described mixture of spraying drying is to form spray-dired powder; And

(f) randomly, basicity source and described alkaline slurry and/or described acidic anionic detersive surfactant precursor and/or described mixture are contacted.

2. the method for claim 1, wherein said alkaline slurry comprises the water of 0 weight % to 25 weight %.

3. the described method of each claim as described above, wherein said alkaline slurry comprises the anionic detersive surfactant of 0 weight % to 5 weight %.

4. the described method of each claim as described above wherein side by side joins the basicity source in the described alkaline slurry with described acidic anionic detersive surfactant precursor basically.

5. the described method of each claim as described above, wherein said acidic anionic detersive surfactant precursor comprises C ₈-C ₂₄Alkyl benzene sulphonate (ABS).

6. the described method of each claim as described above, wherein said basicity source comprises sodium hydroxide.

7. the described method of each claim as described above, wherein said basicity source comprises carbonate.

8. the described method of each claim as described above, wherein said basicity source comprises silicate.