TWI586606B - Method of producing iron silicate powder - Google Patents

Description

Method for producing iron citrate powder

The present invention relates to a method for producing iron citrate powder, and more particularly to a method for producing iron silicate powder using an assembled reaction tank.

Iron citrate, also known as fayalite, coexists with magnesium in the earth's crust to form one of the important ores. It is also an indispensable refractory material in steelmaking. It is composed of iron, antimony and oxygen. Iron citrate is easily oxidized and decomposed into cerium oxide and iron oxide at a high temperature, so that it is difficult to produce high-purity iron citrate. The conventional method for producing iron citrate includes a ferroalloy oxidation method, a hydrothermal synthesis method, and a high temperature and high pressure vessel synthesis method.

The bismuth iron alloy oxidation method is to oxidize yttrium iron alloy with high temperature air above 1000 °C. This method can obtain a mixture of iron citrate and iron oxide, but during the cooling process, air is easy to oxidize and decompose iron silicate into triiron tetroxide and two. Osmium oxide, so it is almost impossible to preserve the iron citrate produced by high temperature.

In the hydrothermal synthesis method, a ferrous salt and a soluble citrate are reacted in a high-pressure closed container to produce a nano-sized iron citrate powder in a closed system, but the obtained iron citrate has poor crystallinity and is difficult to be purified. Nano-sized iron citrate powder is highly reactive and environmentally sensitive.

High temperature and high pressure vessel synthesis method is stable oxidation at normal temperature Ferrous and cerium oxide react, however, ferrous oxide is unstable in high-temperature air, and it is easy to first undergo oxidation reaction without reacting with cerium oxide to form iron citrate. Therefore, this synthesis reaction must be performed by using a high-temperature and high-pressure vessel to insulate the air or in an environment where the ferrous oxide can be stably present.

According to the above, it is not necessary to provide a method for producing iron ruthenate, which can produce iron silicate powder having high purity in a high yield.

Accordingly, an aspect of the present invention provides a method for producing iron citrate powder, which utilizes an assembled reaction cell group to obtain a high-purity iron citrate powder in high yield.

A method for producing an iron citrate powder according to the above aspect, the method comprising the steps of: providing an assembled reaction tank set, sealing the pre-reaction material in the chamber, and placing the assembled reaction tank set at 850 ° C to 1050 ° C to The continuous reaction is carried out in-situ for 1 hour to 16 hours.

The assembled reaction tank group comprises a reaction tank body and a clamp group, wherein the material of the reaction tank body is a low carbon steel, a pure iron or a steel material having an alloy content of less than 0.5%. The reaction tank body comprises a hollow cavity body, an upper cover disposed on the hollow cavity body, an upper gasket disposed between the hollow cavity body and the upper cover, a lower cover disposed under the hollow cavity body, and a middle cover body and a lower cover The lower gasket between. The upper cover, the upper spacer, the hollow body, the lower spacer and the lower cover define a chamber in the hollow body. The above clamp set comprises an upper steel sheet, a lower steel sheet and a plurality of fixing devices. The upper steel sheet is disposed on the upper cover, and the edge of the upper steel sheet may be provided with a plurality of first screw holes, and the lower steel sheet is disposed under the lower cover, wherein the edge of the lower steel sheet vertically corresponds to the first screw hole respectively A plurality of second screw holes are provided. a plurality of fixing devices are respectively disposed on the upper and lower pairs The first screw hole and the second screw hole should be used to lock the upper steel sheet and the lower steel sheet.

The above continuous reaction in situ comprises subjecting a material of the pre-reaction material to a reaction vessel to undergo a redox reaction to form a reaction mass, and subjecting the reaction material to a citrate reaction to form an iron citrate powder. The reaction material consists of ferrous oxide and cerium oxide, and the molar ratio of ferrous oxide to cerium oxide is at least 2:1. The yield of the iron citrate powder formed by the reaction is at least 60% by weight.

According to an embodiment of the invention, the foregoing reaction material comprises iron oxide, and the iron oxide comprises iron oxide and triiron tetroxide.

According to an embodiment of the present invention, the assembled reaction vessel set is subjected to a continuous reaction at 950 ° C to 1050 ° C for 1 hour to 16 hours to obtain an iron citrate powder having a yield of at least 90% by weight.

According to an embodiment of the present invention, the assembled reaction vessel set is subjected to a continuous reaction at 850 ° C to 1050 ° C for 1 hour to 4 hours to obtain a ferric citrate powder having a yield of 60 to 99% by weight.

According to an embodiment of the present invention, the assembled reaction vessel set is subjected to a continuous reaction at 950 ° C to 1050 ° C for 1 hour to 4 hours to obtain a ferric citrate powder having a yield of 90% by weight to 99% by weight.

According to an embodiment of the present invention, the above iron citrate powder has an average particle diameter of from 2 μm to 6 μm.

According to an embodiment of the present invention, the residual amount of the ferrous oxide in the iron citrate powder is not more than 30% by weight.

According to an embodiment of the invention, the molar ratio of the ferrous oxide to the cerium oxide is from 2:1 to 3:1.

According to an embodiment of the invention, the material of the clamp set is stainless steel or a steel material containing nickel or molybdenum alloy.

According to an embodiment of the invention, the fixing device may comprise, for example, a plurality of bolts and a plurality of nuts.

The method for manufacturing the iron ruthenate powder of the invention, which uses the assembled reaction tank group to seal the pre-reaction material, so that the pre-reaction material is in the reaction tank of the assembled reaction tank group, and is in-situ at a high temperature. By performing a continuous reaction of redox and citrate, a high-purity crystalline iron citrate powder can be obtained, which not only greatly increases the yield of iron citrate powder, but also simplifies the process and reduces the equipment cost.

100‧‧‧Assembly reaction tank

101‧‧‧Reaction tank

110‧‧‧ hollow body

112‧‧‧Upper gasket

114‧‧‧Upper cover

116‧‧‧ Lower gasket

118‧‧‧Under the cover

120‧‧‧ chamber

121‧‧‧ Fixture set

122‧‧‧Upper steel sheet

124‧‧‧ Lower steel sheet

126‧‧‧First screw hole

128‧‧‧Second screw hole

129‧‧‧Fixed devices

130‧‧‧ bolt

132‧‧‧ nuts

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; A partial exploded view of the group.

[Fig. 1B] is a schematic view of an assembled reaction tank group assembled in accordance with Fig. 1A.

2 is an X-ray Diffraction (XRD) analysis diagram before the reaction material is unreacted according to an embodiment of the present invention.

3 is an XRD analysis diagram of a reaction mass before reacting at 1050 ° C for 7 minutes according to an embodiment of the present invention.

The invention provides a method for manufacturing iron citrate powder, the method comprising the steps of: providing an assembled reaction tank set, sealing a pre-reaction material in a chamber, and placing the assembled reaction tank set at 850 ° C to 1050 ° C for continuous reaction Up to 1 hour to 16 hours.

1A and FIG. 1B, FIG. 1A is a partially exploded view of an assembled reaction cell set 100 according to an embodiment of the present invention, and FIG. 1B is a schematic view of the assembled reaction cell set 100 assembled according to FIG. 1A. . In one embodiment, the assembled reaction vessel set 100 includes a reaction vessel body 101 and a clamp set 121. The reaction tank body 101 includes a hollow cavity body 110, an upper cover 110 disposed above the hollow cavity body 110, an upper gasket 112 disposed between the hollow cavity body 110 and the upper cover 114, and a lower cover 118 disposed below the hollow cavity body 110. A lower spacer 116 is disposed between the hollow body 110 and the lower cover 118. The upper cover 114, the upper spacer 112, the hollow cavity 110, the lower spacer 116 and the lower cover 118 define a chamber 120 in the hollow cavity 110. The material of the reaction tank body 101 is a low carbon steel, pure iron or steel material having an alloy content of less than 0.5%. It is explained herein that since oxygen easily affects the reaction of synthesizing iron citrate, the present invention utilizes the material of the reaction vessel 101 to first react with oxygen to react most of the oxygen in the chamber 120. Alternatively, iron powder may be added to the chamber 120 of the reaction tank body 101 so that the iron powder first reacts most of the oxygen in the chamber 120. Therefore, the iron ruthenate powder is produced by the assembled reaction vessel group 100 of the present invention, and it is not necessary to introduce an inert gas or a vacuum in the chamber 120.

In one embodiment, the reaction tank body 101 of the assembled reaction tank group 100 is further provided with a clamp group 121 as shown in FIG. 1A. Fixture set 121 contains The upper steel sheet 122, the lower steel sheet 124 and a plurality of fixing devices 129 (for example, a plurality of bolts 130 and a plurality of nuts 132). In an example, the material of the jig set 121 may be, for example, stainless steel or a high-temperature heat-resistant material such as a steel material containing nickel or a molybdenum alloy. The upper steel sheet 122 is disposed on the upper cover 114, and the edge of the upper steel sheet 122 (the upper steel sheet 122 may be any shape) may be provided with a plurality of first screw holes 126, and the lower steel sheet 124 is disposed under the lower cover 118. The edge of the lower steel piece 124 (the lower steel piece 124 may be any shape) is vertically disposed corresponding to the first screw hole 126, and a plurality of second screw holes 128 are respectively disposed. In FIG. 1A, the fixing device 129 can include, for example, a plurality of bolts 130 and a plurality of nuts 132. The bolts 130 are respectively disposed on the first and second screw holes 126 and 128 corresponding to the upper and lower holes, and are locked by the nut 132. Upper steel sheet 122 and lower steel sheet 124. After assembling the above unit, as shown in FIG. 1B, it is a device that can withstand high temperature and seal the assembled reaction tank group 100. It is explained here that the size and size of the assembled reaction tank set 100 can be arbitrarily adjusted according to requirements. For example, the volume of the chamber 120 can be, for example, 1 to 50 ml to produce 0.5 to 35 g of iron citrate powder. .

One of the features of the method of the present invention is the use of the assembled reaction vessel set 100 of Figures 1A and 1B to produce iron ruthenate powder in situ without the need for additional inert gas introduction or vacuuming. In one embodiment, first, a pre-reaction material comprising iron oxide and cerium oxide is sealed in the chamber 120 of the reaction tank body 101. The iron oxide may be, for example, iron oxide (Fe ₂ O ₃ ) and triiron tetroxide (Fe ₃ O ₄ ). Next, the assembled reaction vessel group 100 is placed in a constant temperature high temperature furnace heated to between 850 ° C and 1050 ° C to carry out the reaction for 1 to 16 hours. In the reaction zone of 850 ° C to 1050 ° C, the higher the temperature, the more complete the reaction, that is, the higher the yield of the product. If the reaction temperature is lower than 850 ° C, the yield of the product is low. However, if the reaction temperature is too high, since the eutectic point of iron citrate and ferrous oxide is about 1173 ° C, at this temperature, iron citrate and ferrous oxide will undergo eutectic reaction to produce a liquid. Therefore, the reaction temperature is set to a maximum of 1050 ° C to avoid the heating temperature close to the eutectic point of iron citrate and ferrous oxide.

The iron oxide in the pre-reaction material undergoes a redox reaction with the material of the reaction tank body 101 (for example, carbon steel) at the initial stage of the reaction to form ferrous oxide. Please refer to FIG. 2 and FIG. 3, which are diagrams showing XRD patterns after not reacting and reacting at 1050 ° C for 7 minutes, respectively, according to an embodiment of the present invention, and FIG. 2 shows only iron oxide and cerium oxide of the former reaction material. After the reaction was carried out for 7 minutes at a reaction temperature of 1050 ° C, FIG. 3 shows iron oxide having ferrous oxide, cerium oxide and iron citrate in the solid powder, but no pre-reaction material. After the iron oxide of the former reaction material is reacted for a short period of time, it is completely converted into ferrous oxide of the reaction material. Further, it is understood from the diffraction peak of iron citrate in Fig. 3 that the obtained iron citrate has crystallinity.

Then, the reaction material formed after the redox reaction of the above-mentioned pre-reaction material is subjected to the next oximation reaction in situ to form iron citrate powder. The iron citrate powder can be formed in a yield of at least 60% by weight at a reaction temperature between 850 ° C and 1050 ° C for 1 to 16 hours. In one embodiment, the reaction is carried out at 850 ° C to 1050 ° C for 1 to 4 hours, and the yield of the iron citrate powder is 60% to 99%. In another embodiment, the reaction is carried out at 950 ° C to 1050 ° C for 1 to 16 hours, and the yield of iron citrate powder is at least 90%. In still another embodiment, the reaction is carried out at 950 ° C to 1050 ° C for 1 to 4 hours, and the yield of the iron citrate powder is 90% to 99%. The reaction mass comprises ferrous oxide and cerium oxide, and the molar ratio of ferrous oxide to cerium oxide is at least 2:1. Ferrous oxide and cerium oxide are produced by the reaction of formula (I) in an equivalent ratio of 2:1 to produce iron citrate: 2FeO+SiO ₂ → Fe ₂ SiO ₄ (I)

In the oximation reaction, the ferrous oxide of the formula (I) is produced by reacting a material of the pre-reaction material with the reaction vessel 101. In one example, the molar ratio of ferrous oxide to cerium oxide can be greater than 2:1, with 2:1 to 3:1 being preferred. By controlling the molar ratio of the reaction material to make cerium oxide a limiting agent, it is ensured that sufficient reaction of ferrous oxide and cerium oxide is produced to obtain a high yield of iron silicate powder. If the molar ratio of ferrous oxide to cerium oxide is less than 2:1, the yield and purity of the obtained iron silicate powder may be low.

The following examples are used to illustrate the application of the present invention, and are not intended to limit the present invention. Those skilled in the art can make various changes without departing from the spirit and scope of the present invention. Retouching.

Example 1

The above-mentioned assembled reaction tank group was prepared, and 10.5 g of the reagent grade iron oxide powder and 4.5 g of the cerium oxide powder were weighed. The uniformly mixed powder is placed in the chamber of the reaction tank body, and the upper and lower gaskets are sequentially covered with the upper and lower covers, and then the container is sealed by the clamp group. The assembled reaction tank set was moved into a constant temperature heating furnace which had been heated to 1050 °C. The reaction was carried out at different times. After the reaction was completed, the assembled reaction tank group was taken out, and after cooling, the solid after the reaction in the chamber was taken out and subjected to XRD analysis.

Examples 2 to 3 and Comparative Example 1

Examples 2, 3 and Comparative Example 1 In the same manner as in the procedure of Example 1, only the heating temperature was changed, and the heating temperatures of Examples 2 and 3 were 950 ° C and 850 ° C, respectively, and the heating temperature of Comparative Example 1 was 750 ° C, and the reaction was carried out. After the end, the analysis was also performed by XRD.

Please refer to Table 1, which is a composition content of the solid obtained by the reaction of Examples 1 to 3 and Comparative Example 1 by XRD analysis. As can be seen from Table 1, Comparative Example 1 at 750 ° C, compared with the yield of iron citrate (Fe ₂ SiO ₄ ) obtained in Examples 1 to 3, was between 62.71% and 100%, even though the reaction time was up to The yield of the iron citrate powder was still less than 50% at 16 hours.

By using the method for manufacturing the iron silicate powder of the invention, the reaction material can be sealed before the assembled reaction tank group, and the pre-reaction material is subjected to redox in situ in the reaction tank of the assembled reaction tank group at a high temperature. The continuous reaction of bismuth hydride can be obtained by controlling the molar ratio of ferrous oxide and cerium oxide in the reaction material, and at an appropriate reaction temperature and reaction time. High-purity crystalline iron citrate powder, and greatly improve the yield of iron citrate powder, simplify the process and reduce equipment costs.

100‧‧‧Assembly reaction tank

101‧‧‧Reaction tank

110‧‧‧ hollow body

112‧‧‧Upper gasket

114‧‧‧Upper cover

116‧‧‧ Lower gasket

118‧‧‧Under the cover

120‧‧‧ chamber

121‧‧‧ Fixture set

122‧‧‧Upper steel sheet

124‧‧‧ Lower steel sheet

126‧‧‧First screw hole

128‧‧‧Second screw hole

129‧‧‧Fixed devices

130‧‧‧ bolt

132‧‧‧ nuts

Claims (10)

A method for producing iron citrate powder, comprising: providing an assembled reaction tank set, wherein the assembled reaction tank set comprises: a reaction tank body, wherein one material of the reaction tank body is low carbon steel, pure iron or alloy a steel material having a content of less than 0.5%, and the reaction tank body comprises: a hollow cavity; an upper cover disposed on the hollow cavity; an upper gasket disposed between the hollow cavity and the upper cover; a lower cover under the hollow cavity; and a lower gasket disposed between the hollow cavity and the lower cover, wherein the upper cover, the upper spacer, the hollow body, the lower gasket and the lower cover Determining a chamber in the hollow cavity; and a clamp set disposed outside the reaction tank, and the clamp set comprises: an upper steel sheet disposed on the upper cover, wherein the upper steel sheet is respectively provided with edges a plurality of first screw holes; a lower steel piece disposed under the lower cover, wherein an edge of the lower steel piece vertically corresponding to the first screw holes is respectively provided with a plurality of second screw holes; and a plurality of fixed The device is respectively disposed on the first screw holes corresponding to the upper and lower sides and the second screw holes Locking the upper steel sheet and the lower steel sheet; sealing a pre-reaction material in the chamber; placing the assembled reaction tank group at 850 ° C to 1050 ° C for in-situ a continuous reaction for 1 hour to 16 hours, where The continuous reaction comprises: subjecting the pre-reaction material to the redox reaction of the material of the reaction tank to form a reaction material, wherein the reaction material is composed of ferrous oxide and cerium oxide, and the ferrous oxide is The molar ratio of cerium oxide is at least 2:1; and the reaction material is subjected to a citrate reaction to form an iron citrate powder, wherein one of the iron citrate powders has a yield of at least 60% by weight. The method for producing iron ruthenate powder according to claim 1, wherein the pre-reaction material comprises iron oxide, and the iron oxide comprises iron oxide and triiron tetroxide. The method for producing an iron citrate powder according to claim 1, wherein the assembled reaction tank set is subjected to the continuous reaction at 950 ° C to 1050 ° C for 1 hour to 16 hours to obtain the yield. At least 90% by weight of the iron citrate powder. The method for producing an iron citrate powder according to claim 1, wherein the assembled reaction tank set is subjected to the continuous reaction at 850 ° C to 1050 ° C for 1 hour to 4 hours to obtain the yield. 60% by weight to 99% by weight of the iron citrate powder. The method for producing iron citrate powder according to claim 1, wherein the assembled reaction tank set is placed at 950 ° C to 1050 The continuous reaction is carried out at ° C for 1 hour to 4 hours to obtain the iron citrate powder in a yield of 90% by weight to 99% by weight. The method for producing an iron citrate powder according to the first aspect of the invention, wherein the iron citrate powder has an average particle diameter of from 2 μm to 6 μm. The method for producing iron citrate powder according to claim 1, wherein the residual amount of the ferrous oxide in the iron citrate powder does not exceed 30% by weight. The method for producing iron citrate powder according to claim 1, wherein the molar ratio of the ferrous oxide to the cerium oxide is from 2:1 to 3:1. The method for producing iron silicate powder according to claim 1, wherein the material of the jig set is stainless steel or a steel material containing nickel or molybdenum alloy. The method for producing iron silicate powder according to claim 1, wherein the fixing device comprises a plurality of bolts and a plurality of nuts.