CN114804119A - Silicon dioxide particle size control process - Google Patents

Abstract

Translated fromChinese

本发明公开了一种二氧化硅粒径控制方法，二氧化硅颗粒是由二氧化硅浆料经压力式喷雾干燥塔干燥而成；压力式喷雾干燥塔包括喷嘴以及设置在喷嘴出料口处的喷片，喷片上开设有喷片通孔；二氧化硅颗粒的粒径控制主要是通过对喷片通孔的孔径、压力式喷雾干燥塔的喷雾压力、二氧化硅浆料的含固量以及二氧化硅浆料粘度进行调整实现的。本发明的技术方案在二氧化硅的压力干燥喷雾阶段通过调节浆料含固量、浆料粘度及温度、喷片孔径、喷雾压力等因素，同时增加了流化床二次干燥工艺，实现最终产品颗粒粒度分布状况可控，可以生产多种粒度范围的产品，满足不同行业的各种客户需求。

The invention discloses a method for controlling the particle size of silicon dioxide. The silicon dioxide particles are obtained by drying silicon dioxide slurry through a pressure type spray drying tower; the pressure type spray drying tower comprises a nozzle and is arranged at the outlet of the nozzle. The spray sheet is provided with spray sheet through holes; the particle size of the silica particles is mainly controlled by the pore size of the spray sheet through holes, the spray pressure of the pressure spray drying tower, and the solid content of the silica slurry. And the viscosity of the silica slurry is adjusted to achieve. The technical scheme of the present invention increases the fluidized bed secondary drying process by adjusting factors such as the solid content of the slurry, the viscosity and temperature of the slurry, the pore diameter of the spray sheet, and the spray pressure in the pressure drying and spraying stage of the silica, so as to achieve the final result. The particle size distribution of the product is controllable, and products with a variety of particle size ranges can be produced to meet various customer needs in different industries.

Description

Translated fromChinese

一种二氧化硅粒径控制工艺A kind of silica particle size control technology

技术领域technical field

本发明涉及二氧化硅生产技术领域，尤其是一种二氧化硅粒径控制工艺。The invention relates to the technical field of silicon dioxide production, in particular to a process for controlling the particle size of silicon dioxide.

背景技术Background technique

随着二氧化硅应用行业的不断拓展，对产品的要求也越来越高，且不同的用户对二氧化硅颗粒的性能要求也不一,有用户要求物料颗粒尽可能细小、均匀；也有用户要求粉料大颗粒尽可能多、均匀。这就要求制造商应该熟练掌握二氧化硅颗粒粒度分布控制技术，可以生产不同粒度分布范围的产品,去满足不同的行业需求和客户要求。With the continuous expansion of the silica application industry, the requirements for products are getting higher and higher, and different users have different performance requirements for silica particles. Some users require material particles to be as small and uniform as possible; some users It is required that the large particles of powder are as many and uniform as possible. This requires that manufacturers should be proficient in the control technology of silica particle size distribution, and can produce products with different particle size distribution ranges to meet different industry needs and customer requirements.

目前在压力式喷雾干燥二氧化硅的生产过程中，所得的物料颗粒级配不理想，粒径两极分化明显，有时颗粒粒度过大，有时又会产生大量的细粉料，粒度分布很宽，颗粒尺寸、硬度不均匀不能满足高端用户需求。颗粒粒度过大容易产生大量废料，生产成本升高；而产品中细粉末过多易造成粉尘飞扬，不能满足客户的环保要求。At present, in the production process of pressure spray-dried silica, the particle gradation of the obtained material is not ideal, and the particle size polarization is obvious. Sometimes the particle size is too large, and sometimes a large amount of fine powder is produced, and the particle size distribution is very wide. The uneven particle size and hardness cannot meet the needs of high-end users. If the particle size is too large, it is easy to generate a large amount of waste, and the production cost will increase; and too much fine powder in the product will easily cause dust to fly, which cannot meet the environmental protection requirements of customers.

发明内容SUMMARY OF THE INVENTION

本发明针对现有技术中存在的不足之处，提供一种二氧化硅粒径控制工艺。Aiming at the deficiencies in the prior art, the present invention provides a process for controlling the particle size of silicon dioxide.

本发明的目的是以下述方式实现的：The purpose of this invention is to realize in the following way:

一种二氧化硅粒径控制方法，二氧化硅颗粒是由二氧化硅浆料经压力式喷雾干燥塔干燥而成；所述压力式喷雾干燥塔包括喷嘴以及设置在所述喷嘴出料口处的喷片，所述喷片上开设有喷片通孔；所述二氧化硅颗粒的粒径控制主要是通过对所述喷片通孔的孔径、所述压力式喷雾干燥塔的喷雾压力、所述二氧化硅浆料的含固量以及所述二氧化硅浆料粘度进行调整实现的。A method for controlling the particle size of silicon dioxide. The silicon dioxide particles are obtained by drying silicon dioxide slurry through a pressure-type spray-drying tower; the pressure-type spray-drying tower comprises a nozzle and a nozzle disposed at the outlet of the nozzle. The spray sheet is provided with a spray sheet through hole; the particle size of the silica particles is controlled mainly by the aperture of the spray sheet through hole, the spray pressure of the pressure spray drying tower, and the It is realized by adjusting the solid content of the silica slurry and the viscosity of the silica slurry.

作为本发明技术方案的一种可选方案，所述压力式喷雾干燥塔包括塔体、喷嘴、高压供料泵、热风分布器、布袋除尘器以及引风机，所述高压供料泵的压力将所述二氧化硅料胶料通过所述喷嘴形成细微液滴，再经与热风进行充分热交换得以快速干燥，从而得到所述二氧化硅颗粒。As an optional solution of the technical solution of the present invention, the pressure spray drying tower includes a tower body, a nozzle, a high-pressure feed pump, a hot air distributor, a bag filter and an induced draft fan, and the pressure of the high-pressure feed pump will be The silica sizing material forms fine droplets through the nozzle, and is then rapidly dried by sufficient heat exchange with hot air, thereby obtaining the silica particles.

作为本发明技术方案的一种可选方案，经过所述压力式喷雾干燥塔干燥后的二氧化硅颗粒的含水率为11.4％～12.6％，该二氧化硅颗粒经流化床进行二次干燥后，使得含水率降至5.2％～5.9％后由所述流化床的出料口排出。As an optional solution of the technical solution of the present invention, the moisture content of the silica particles dried by the pressure spray drying tower is 11.4% to 12.6%, and the silica particles are subjected to secondary drying through the fluidized bed. After that, the water content is reduced to 5.2% to 5.9% and then discharged from the outlet of the fluidized bed.

作为本发明技术方案的一种可选方案，所述流化床是包括床身、筛板、加热器、鼓风机；所述压力式喷雾干燥后的二氧化硅颗粒经所述流化床的进料口进入流化床内，过滤后的洁净空气经所述加热器加热后由所述鼓风机送入流化床底部，经所述筛板与所述二氧化硅颗粒接触，形成流化态达到气固的热质交换达到干燥的目的。As an optional solution of the technical solution of the present invention, the fluidized bed includes a bed, a sieve plate, a heater, and a blower; the silica particles after the pressure spray drying are fed through the fluidized bed. The material inlet enters the fluidized bed, and the filtered clean air is heated by the heater and sent to the bottom of the fluidized bed by the blower, and contacts the silica particles through the sieve plate to form a fluidized state. The heat and mass exchange between gas and solid achieves the purpose of drying.

作为本发明技术方案的一种可选方案，所述二氧化硅的粒径为20～60目时，所述喷片通孔孔径为2.6～3.0mm，所述压力式喷雾干燥塔的喷雾压力为1.2～1.5MPa，所述二氧化硅浆料的含固量为25～30％，所述二氧化硅浆料粘度＜500CPs，所述流化床内温度为32～36℃。As an optional solution of the technical solution of the present invention, when the particle size of the silica is 20-60 mesh, the diameter of the through holes of the spray sheet is 2.6-3.0 mm, and the spray pressure of the pressure spray drying tower 1.2-1.5MPa, the solid content of the silica slurry is 25-30%, the viscosity of the silica slurry is less than 500CPs, and the temperature in the fluidized bed is 32-36°C.

作为本发明技术方案的一种可选方案，所述二氧化硅粒径为40～80目时，所述喷片通孔孔径为2.1～2.5mm，所述压力式喷雾干燥塔的喷雾压力为1.7～2.2MPa，所述二氧化硅浆料的含固量为22～25％，所述二氧化硅浆料粘度为500～1000CPs，所述流化床内温度为32～36℃。As an optional solution of the technical solution of the present invention, when the particle size of the silica is 40-80 mesh, the diameter of the through holes of the spray sheet is 2.1-2.5 mm, and the spray pressure of the pressure-type spray drying tower is 1.7-2.2MPa, the solid content of the silica slurry is 22-25%, the viscosity of the silica slurry is 500-1000CPs, and the temperature in the fluidized bed is 32-36°C.

作为本发明技术方案的一种可选方案，所述二氧化硅粒径为60～150目时，所述喷片通孔孔径为1.6～2.0mm，所述压力式喷雾干燥塔的喷雾压力为2.5～3.5MPa，所述二氧化硅浆料的含固量为10～20％，所述二氧化硅浆料粘度为1000～2000CPs，所述流化床内温度为52～56℃。As an optional solution of the technical solution of the present invention, when the particle size of the silica is 60-150 mesh, the through-hole diameter of the spray sheet is 1.6-2.0 mm, and the spray pressure of the pressure spray drying tower is 2.5-3.5MPa, the solid content of the silica slurry is 10-20%, the viscosity of the silica slurry is 1000-2000 CPs, and the temperature in the fluidized bed is 52-56°C.

本发明的有益效果是：The beneficial effects of the present invention are:

本发明的技术方案在二氧化硅的压力干燥喷雾阶段通过调节浆料含固量、浆料粘度及温度、喷片孔径、喷雾压力等因素，同时增加了流化床二次干燥工艺，实现最终产品颗粒粒度分布状况可控，可以生产多种粒度范围的产品，满足不同行业的各种客户需求。The technical scheme of the present invention adjusts factors such as the solid content of the slurry, the viscosity and temperature of the slurry, the pore diameter of the spray sheet, the spray pressure and other factors in the pressure drying and spraying stage of the silica, and at the same time increases the secondary drying process of the fluidized bed, so as to achieve the final result. The particle size distribution of the product is controllable, and products with a variety of particle size ranges can be produced to meet various customer needs in different industries.

附图说明Description of drawings

为了更清楚地说明本发明实施例中的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动性的前提下，还可以根据这些附图获得其他的附图。In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

图1为本发明实施例中喷嘴结构的示意图。FIG. 1 is a schematic diagram of a nozzle structure in an embodiment of the present invention.

图2为本发明实施例中流化床的结构示意图。FIG. 2 is a schematic structural diagram of a fluidized bed in an embodiment of the present invention.

附图标记：Reference number:

10-喷嘴座；11-旋流片；12-喷片；13-外壳；14-挡片；15-喷嘴腔；20-流化床；21-床身；22-筛板；23-出料口；24-进风口；25-进料口。10-nozzle seat; 11-swirl plate; 12-spray plate; 13-shell; 14-block plate; 15-nozzle cavity; 20-fluidized bed; 21-bed body; 22-sieve plate; 23-discharge port; 24-air inlet; 25-feeding port.

具体实施方式Detailed ways

下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments.

需要说明，本发明实施例中所有方向性指示(诸如上、下、左、右、前、后……)仅用于解释在某一特定姿态(如附图所示)下各部件之间的相对位置关系、运动情况等，如果该特定姿态发生改变时，则该方向性指示也相应地随之改变。It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relationship between various components under a certain posture (as shown in the accompanying drawings). The relative positional relationship, the movement situation, etc., if the specific posture changes, the directional indication also changes accordingly.

在实施例的描述中，除非另有明确的规定和限定，术语“设置”、“连接”等应做广义理解。例如，可以是固定连接，也可以是可拆卸连接，或一体连接；可以是机械连接，也可以是电连接；可以是直接相连，也可以通过中介媒体相连，还可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以具体情况理解上述术语在本发明中的具体含义。In the description of the embodiments, the terms "arrangement", "connection" and the like should be construed in a broad sense unless otherwise explicitly specified and limited. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or a connection through an intermediary medium, or a connection between the two components. . For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

压力式喷雾干燥塔是合成二氧化硅常用的一种同时完成干燥和造粒的设备，整个干燥系统由干燥塔、喷嘴、高压供料泵、热风分布器、布袋除尘器、引风机等组成。工作过程是借助高压供料泵的压力将二氧化硅料浆通过喷嘴雾化为细微液滴，雾滴经与热风进行充分热交换得以快速干燥十几秒至几十秒，从而得到细小颗粒状二氧化硅产品，喷雾干燥直接影响二氧化硅颗粒的成形性能、颗粒大小、粒度均匀性、粒子强度等，故此过程在二氧化硅生产过程中至关重要。Pressure spray drying tower is a commonly used equipment for simultaneous drying and granulation of synthetic silica. The entire drying system consists of drying tower, nozzle, high-pressure feed pump, hot air distributor, bag filter, and induced draft fan. The working process is to atomize the silica slurry through the nozzle into fine droplets with the help of the pressure of the high-pressure feed pump. For silica products, spray drying directly affects the formability, particle size, particle size uniformity, particle strength, etc. of silica particles, so this process is very important in the production process of silica.

如图1所示，喷嘴主要包括喷嘴座10、旋流片11、外壳13、挡片14以及由外壳围成的喷嘴腔15，喷嘴通过喷嘴座10设置在压力式喷雾干燥塔上，在喷嘴的出料口处放置一个喷片12，喷片12中间开设有喷片通孔，实际工作的过程中可以根据实际需要更换喷片通孔孔径不同的喷片12。As shown in Figure 1, the nozzle mainly includes anozzle seat 10, aswirl sheet 11, acasing 13, abaffle 14 and anozzle cavity 15 surrounded by the casing. Aspray piece 12 is placed at the discharge port of the spray piece, and a spray piece through hole is opened in the middle of thespray piece 12. During the actual working process, thespray piece 12 with different diameters of the spray piece through hole can be replaced according to actual needs.

本发明以调节浆料自身的相关参数以及调整喷片通孔孔径和喷雾压力，再通过流化床技术去除细粉的综合手段来控制粒度分布。The invention controls the particle size distribution by comprehensive means of adjusting the relevant parameters of the slurry itself, adjusting the diameter of the through holes and the spray pressure of the spray sheet, and then removing the fine powder through the fluidized bed technology.

1、技术解决方案1. Technical solutions

1)通过调节浆料自身参数进而调控颗粒粒度分布和颗粒强度1) Adjust the particle size distribution and particle strength by adjusting the parameters of the slurry itself

①浆料含固量：经试验，在喷片孔径和喷雾压力不变的情况下，浆料含固量升高，喷雾所得颗粒变大，60目以上颗粒比例增多，100目以下细粉比例减少，粒径分布变窄，产品粒度整体偏粗，同时，颗粒的强度有所提高。适合生产粗大粒径、产量较高的产品。①Solid content of slurry: After the test, under the condition that the diameter of the spray sheet and the spray pressure remain unchanged, the solid content of the slurry increases, the particles obtained by spraying become larger, the proportion of particles above 60 mesh increases, and the proportion of fine powder below 100 mesh If the particle size is reduced, the particle size distribution is narrowed, and the overall particle size of the product is coarser, and at the same time, the strength of the particle is improved. It is suitable for producing products with coarse particle size and high output.

②浆料粘度：在浆料含固量和喷片孔径、喷雾压力保持不变的前提下，通过在浆料中添加不同种类的表面改性剂对浆料进行粘度调节,发现粘度更大的浆料在喷雾干燥后粒径偏大，粒径分布更窄，产品粒度整体偏粗，适合生产中粗粒径的产品。增稠型的表面改性剂可选用聚丙烯酰胺或氢氧化钠溶液，用来提高浆料粘度；降粘型的表面改性剂可选用偏硅酸钠或醋酸溶液，用来降低浆料粘度。②Slurry viscosity: On the premise that the solid content of the slurry, the diameter of the spray sheet, and the spray pressure remain unchanged, the viscosity of the slurry is adjusted by adding different types of surface modifiers to the slurry. The particle size of the slurry after spray drying is larger, the particle size distribution is narrower, and the overall particle size of the product is coarse, which is suitable for the production of products with medium and coarse particle size. The thickening type surface modifier can choose polyacrylamide or sodium hydroxide solution to increase the viscosity of the slurry; the viscosity reducing type surface modifier can choose sodium metasilicate or acetic acid solution to reduce the slurry viscosity .

③浆料温度：对正在进行的喷雾过程进行浆料加温，当温度从35℃升高到55℃并稳定后，所得干燥产品整体偏细，100目以下细粉比例增多，但粒径分布变化不明显，适合生产中细粒径的产品。③Slurry temperature: The slurry is heated during the ongoing spraying process. When the temperature rises from 35°C to 55°C and stabilizes, the obtained dried product is generally fine, and the proportion of fine powder below 100 mesh increases, but the particle size distribution The change is not obvious, and it is suitable for the production of products with medium and fine particle size.

2)通过调节喷片孔径和喷雾压力控制颗粒粒度分布：2) Control the particle size distribution by adjusting the pore size of the spray blade and the spray pressure:

①当其他工艺和设备参数一定时，喷片孔径增加，雾滴直径大，干燥后的颗粒偏粗，粒径分布偏窄；喷片孔径减小，雾滴直径小，干燥后的颗粒偏细，粒径分布偏宽。在生产中，按照二氧化硅的不同用途可将不同孔径的喷片搭配使用，以得到理想的颗粒粒度级配。①When other process and equipment parameters are constant, the diameter of spray plate increases, the diameter of droplets is large, the particles after drying are coarser, and the particle size distribution is narrow; the diameter of spray plate decreases, the diameter of droplets is small, and the particles after drying Fine, the particle size distribution is broad. In production, according to the different uses of silica, spray sheets with different apertures can be used together to obtain the ideal particle size distribution.

②当其他工艺和设备参数一定时，喷雾压力越大，二氧化硅物料中细颗粒所占比例越大，粒径分布越宽；喷雾压力越小，物料中粗颗粒所占比例越大，粒径分布越窄。但压力过低，喷雾干燥塔生产能力下降，成本大幅度上升。喷雾压力过大，喷片寿命明显下降，粒径分布范围飘移不定。②When other process and equipment parameters are constant, the greater the spray pressure, the greater the proportion of fine particles in the silica material, and the wider the particle size distribution; the smaller the spray pressure, the greater the proportion of coarse particles in the material, The narrower the particle size distribution. However, if the pressure is too low, the production capacity of the spray drying tower will decrease, and the cost will increase significantly. If the spray pressure is too large, the life of the spray plate will be significantly reduced, and the particle size distribution range will drift.

调整喷片孔径和喷雾压力虽然是最便捷的粒径控制措施，但有一定的局限性，改变浆料的理化性质，更容易从根本上解决问题。Although adjusting the pore size and spray pressure of the spray sheet is the most convenient particle size control measure, it has certain limitations. It is easier to fundamentally solve the problem by changing the physical and chemical properties of the slurry.

3)用流化床技术控制粒度分布：3) Use fluidized bed technology to control particle size distribution:

流化床是用热空气鼓入放置有湿物料的床层中，使颗粒流态化从而提高传热系数使物料干燥的设备。流化床20是包括床身21、筛板22、加热器、鼓风机；压力式喷雾干燥后的二氧化硅颗粒经所述流化床的进料口25进入流化床内，过滤后的洁净空气经加热器加热后由鼓风机通过进风口24送入流化床底部，经筛板与所述二氧化硅颗粒接触，形成流化态达到气固的热质交换达到干燥的目的，物料经过再次干燥后由出料口23排出。运用流化技术的目的是对二氧化硅颗粒进行二次干燥，在可调的负压状态下，根据不同客户对产品粒度分布的不同要求，选择性去除二氧化硅微珠中的细粉，使颗粒粒度更均匀，分布更窄；同时得到的二氧化硅细粉末，可做为衍生的特殊粒径产品进行针对性销售，提高附加值。The fluidized bed is a device that uses hot air to blow into the bed where the wet material is placed to fluidize the particles, thereby increasing the heat transfer coefficient and drying the material. Thefluidized bed 20 includes abed 21, asieve plate 22, a heater, and a blower; the silica particles after pressure spray drying enter the fluidized bed through thefeed port 25 of the fluidized bed, and the filtered clean After the air is heated by the heater, the air is sent to the bottom of the fluidized bed by the blower through theair inlet 24, and is contacted with the silica particles through the sieve plate to form a fluidized state to achieve gas-solid heat and mass exchange to achieve the purpose of drying. After drying, it is discharged from thedischarge port 23. The purpose of using fluidization technology is to perform secondary drying of silica particles. Under the adjustable negative pressure state, according to the different requirements of different customers for product particle size distribution, the fine powder in the silica microbeads can be selectively removed. The particle size is more uniform and the distribution is narrower; at the same time, the obtained silicon dioxide fine powder can be used as a derivative special particle size product for targeted sales and increase the added value.

2、技术效果2. Technical effect

1)选用较大的喷片孔径(2.6～3.0mm)，较低的喷雾压力(1.2～1.5MPa)，较高的浆料含固量(25～30％)，较低的浆料粘度(<500CPS)，可得到核心粒径20～60目的粒度，该范围在粒径分布中占比80％以上，属于较窄的粒径分布，市售产品该范围占比60％左右。该方案可以生产大颗粒二氧化硅，用于橡胶制品特别是高性能轮胎的环保性补强剂。1) Choose larger nozzle aperture (2.6~3.0mm), lower spray pressure (1.2~1.5MPa), higher slurry solid content (25~30%), lower slurry viscosity ( <500CPS), the core particle size of 20-60 mesh can be obtained, and this range accounts for more than 80% of the particle size distribution, which belongs to a narrow particle size distribution, and this range of commercial products accounts for about 60%. This solution can produce large-particle silica, which can be used as an environmentally friendly reinforcing agent for rubber products, especially high-performance tires.

2)选用中粗的喷片孔径(2.1～2.5mm)，适中的喷雾压力(1.7～2.2MPa)，正常的浆料含固量(22～25％)，正常的浆料粘度(<1000CPS)，可得到核心粒径40～80目的粒度，该范围在粒径分布中占比80％以上，属于较窄的粒径分布，市售产品该范围占比不足70％。该方案可以生产中等粒径二氧化硅，用于橡胶助剂、维生素、酸味剂等油状物品的吸附载体。2) Select medium and coarse spray sheet aperture (2.1~2.5mm), moderate spray pressure (1.7~2.2MPa), normal slurry solid content (22~25%), normal slurry viscosity (<1000CPS) , the core particle size of 40-80 mesh can be obtained, and this range accounts for more than 80% of the particle size distribution, which belongs to a narrow particle size distribution, and the range of commercial products accounts for less than 70%. This solution can produce medium-sized silica, which is used as an adsorption carrier for oily items such as rubber additives, vitamins, and sour agents.

3)选用较小的喷片孔径(1.6～2.0mm)，较高的喷雾压力(2.5～3.5MPa)，较低的浆料含固量(18～20％)，较高的浆料粘度(1000～2000CPS)，可得到核心粒径60～150目的粒度，该范围在粒径分布中占比85％以上，属于较宽的粒径分布，市售产品该范围占比不足65％。该方案可以生产粒度分布较宽的小颗粒二氧化硅，用于氯化胆碱、乙氧基喹啉、大蒜素等液体饲料添加剂的载体稀释剂。3) Select smaller nozzle aperture (1.6-2.0mm), higher spray pressure (2.5-3.5MPa), lower slurry solid content (18-20%), higher slurry viscosity ( 1000-2000CPS), the core particle size of 60-150 mesh can be obtained, and this range accounts for more than 85% of the particle size distribution, which belongs to a wider particle size distribution, and the range of commercial products accounts for less than 65%. This solution can produce small particle silica with wide particle size distribution, which is used as a carrier diluent for liquid feed additives such as choline chloride, ethoxyquin, and allicin.

以下通过几个实施例对本发明效果进行具体说明。The effects of the present invention will be specifically described below through several embodiments.

实施例1，Example 1,

二氧化硅浆料含固量27.0％，喷片孔径3.0mm，喷雾压力1.5MPa,浆料粘度500CPS，浆料温度35℃，测定产品粒度分布情况如下：The solid content of the silica slurry is 27.0%, the diameter of the spray sheet is 3.0mm, the spray pressure is 1.5MPa, the viscosity of the slurry is 500CPS, and the temperature of the slurry is 35℃. The particle size distribution of the product is determined as follows:

20目以上：2.1％；Above 20 mesh: 2.1%;

20-40目：35.3％；20-40 mesh: 35.3%;

40-60目：46.8％；40-60 mesh: 46.8%;

60目以下：15.8％。Below 60 mesh: 15.8%.

实施例2，Example 2,

二氧化硅浆料含固量23.6.0％，喷片孔径2.4mm，喷雾压力2.0MPa,浆料粘度880CPS，浆料温度35℃，测定产品粒度分布情况如下：The solid content of the silica slurry is 23.6.0%, the diameter of the spray sheet is 2.4mm, the spray pressure is 2.0MPa, the slurry viscosity is 880CPS, and the slurry temperature is 35℃. The particle size distribution of the product is determined as follows:

40目以上：7.6％；Above 40 mesh: 7.6%;

40-60目：40.5％；40-60 mesh: 40.5%;

60-80目：41.7％；60-80 mesh: 41.7%;

80目以下：10.82。Below 80 mesh: 10.82.

实施例3，Example 3,

二氧化硅浆料含固量19.2％，喷片孔径1.8mm，喷雾压力3.5MPa,浆料粘度1600CPS，浆料温度55℃，测定产品粒度分布情况如下：The solid content of the silica slurry is 19.2%, the diameter of the spray sheet is 1.8mm, the spray pressure is 3.5MPa, the slurry viscosity is 1600CPS, and the slurry temperature is 55℃. The particle size distribution of the product is determined as follows:

60目以上：3.8％；Above 60 mesh: 3.8%;

60-100目：47.7％；60-100 mesh: 47.7%;

100-150目：40.9％；100-150 mesh: 40.9%;

150目以下：7.6％。Below 150 mesh: 7.6%.

以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。另外，各个实施例之间的技术方案可以相互结合，但是必须是以本领域普通技术人员能够实现为基础；当技术方案的结合出现相互矛盾或无法实现时应当认为这种技术方案的结合不存在，也不在本发明要求的保护范围之内。The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the present invention. within the scope of protection. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art; when the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist. , is not within the scope of protection required by the present invention.

Claims (7)

1. A method for controlling the particle size of silicon dioxide is characterized in that silicon dioxide particles are formed by drying silicon dioxide slurry through a pressure type spray drying tower; the pressure type spray drying tower comprises a nozzle and a spray sheet arranged at a discharge port of the nozzle, and the spray sheet is provided with a spray sheet through hole;

the particle size control of the silica particles is mainly realized by adjusting the aperture of the spray sheet through hole, the spray pressure of the pressure type spray drying tower, the solid content of the silica slurry and the viscosity of the silica slurry.

2. The method for controlling the particle size of silica according to claim 1, wherein the pressure-type spray drying tower comprises a tower body, a nozzle, a high-pressure feed pump, a hot air distributor, a bag-type dust collector and an induced draft fan, wherein the silica material is formed into fine droplets through the nozzle by the pressure of the high-pressure feed pump, and then the fine droplets are rapidly dried by sufficient heat exchange with hot air, so that the silica particles are obtained.

3. The method for controlling the particle size of silica according to claim 1, wherein the silica particles dried by the pressure type spray drying tower have a water content of 11.4 to 12.6%, and the silica particles are discharged from a discharge port of the fluidized bed after being secondarily dried by the fluidized bed to have a water content of 5.2 to 5.9%.

4. The silica particle size control method according to claim 2, wherein the fluidized bed is a fluidized bed comprising a bed, a sieve plate, a heater, a blower; the pressure type spray-dried silicon dioxide particles enter the fluidized bed through the feed inlet of the fluidized bed, the filtered clean air is heated by the heater and then is sent to the bottom of the fluidized bed by the air blower, and the filtered clean air is contacted with the silicon dioxide particles through the sieve plate to form a fluidized state so as to achieve the purpose of gas-solid heat-mass exchange and drying.

5. The method for controlling the particle size of silica according to claim 2, wherein when the particle size of silica is 20 to 60 mesh, the pore diameter of the spray sheet through hole is 2.6 to 3.0mm, the spray pressure of the pressure type spray drying tower is 1.2 to 1.5MPa, the solid content of the silica slurry is 25 to 30%, the viscosity of the silica slurry is less than 500CPs, and the temperature in the fluidized bed is 32 to 36 ℃.

6. The method for controlling the particle size of silica according to claim 2, wherein when the particle size of silica is 40 to 80 mesh, the pore diameter of the spray sheet through hole is 2.1 to 2.5mm, the spray pressure of the pressure type spray drying tower is 1.7 to 2.2MPa, the solid content of the silica slurry is 22 to 25%, the viscosity of the silica slurry is 500 to 1000CPs, and the temperature in the fluidized bed is 32 to 36 ℃.

7. The method for controlling the particle size of silica according to claim 2, wherein when the particle size of silica is 60 to 150 mesh, the pore diameter of the spray sheet through hole is 1.6 to 2.0mm, the spray pressure of the pressure type spray drying tower is 2.5 to 3.5MPa, the solid content of the silica slurry is 10 to 20%, the viscosity of the silica slurry is 1000 to 2000CPs, and the temperature in the fluidized bed is 52 to 56 ℃.

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