CN1033799C - Method for preparing calcium borate from boron ore - Google Patents

Abstract

The invention discloses a method for using ACaO EB₂O₃·nH₂A process for producing calcium borate (A-1-5, E-1-11, n-0-20) series represented by O. The method comprises calcifying borate solution obtained by decomposing ore, etc. with calcium nitrate and calcium hydroxide, adjusting pH with calcium hydroxide or ammonium hydroxide, etc. to obtain calcium borate, and passing Ca (NO) solution₃)₂、Ca(OH)₂Different calcium borate can be obtained by adjusting different pH values and adding different amounts, the original ammonia distillation process can be omitted, the flow is simplified, and the energy consumption is reduced. In the process of the invention, particularly, a pressure filter press is adopted to carry out solid-liquid separation in the calcification process, so that the loss of boron and the consumption of water and steam can be greatly reduced, and the total recovery rate of boron is improved. The borate solution can be prepared from 60 different boron ores, chemicals or industrial products, and is particularly suitable for ores with low grade and hardness more than 4, so that a raw material source for preparing calcium borate is developed. The obtained product contains B₂O₃34～67%，CaO21～33%，NH₄NO₃0.2 to 12 percent. The product can be crystal or amorphous superfine powder.

Description

The invention relates to a method for preparing inorganic salts, more specifically, a method for preparing calcium borate from boron ore containing sodium, potassium, ammonium, magnesium, calcium, strontium, manganese and iron.

There are many methods for producing calcium borate, such as boric acid oxidation method, ammonium borate calcium oxide method, sodium metaborate and calcium oxide method, etc. Some of these methods have high costs, some have long reaction cycles, and some contain harmful substances such as chloride ions. And the above-mentioned methods all can only produce a kind of calcium borate (namely CaB ₂ O ₄ nH ₂ O). In CN88103561, a series of calcium borates represented by ACaO EB ₂ O ₃ nH ₂ O (A is 1～ 2, E is 1-5, n is 0-20). In this method, calcium nitrate can be prepared by calcining limestone and reacting with ammonium nitrate. Ammonium or alkali metal borate or polyborate can be obtained by leaching boron ore with ammonium or alkali metal carbonate or acid carbonate. have to. This method can not only produce a series of calcium borate products, but also shorten the cycle, reduce energy consumption, and some raw materials can be recycled, so the cost is also reduced. However, there is an ammonia distillation and carbonization process in this method, so the process is still long and the energy consumption is relatively high, and this method can only be applied to a small amount of boron ore, and is not suitable for boron ore with high hardness and low grade. Mines other than boron-magnesium ore, Suian stone, boronite, and iron-boron ore have not yet been developed. In addition, the calcified calcium borate solution is separated by a centrifuge, resulting in a large loss of boron, large water consumption, and high energy consumption.

The purpose of the invention is to provide a method for preparing a series of calcium borate products with few steps, low energy consumption and high yield.

The present invention is carried out like this. ACaO·EB ₂ O ₃ ·nH ₂ O (A is 1~5, E is 1~11, n is 0~20) series products. Then adjust the pH value by calcium hydroxide Ca(OH) ₂ or NH ₄ OH, NaOH, KOH, and a series of calcium borates can be directly prepared. Thereby, the ammonia distillation process can be canceled, which not only simplifies the process, shortens the process, but also greatly saves energy consumption. For composite boron raw materials (including ores, industrial products, chemicals) containing alkali metals Na, K, NH ₄ ⁺ and alkaline earth metals Mg, Ca, Sr, the original boron ore powder is pressurized at 140±5°C (0.7 ~2.0MPa) under the mineralolysis reaction, extended to room temperature ~ 67 ℃, the mineralolysis reaction under normal pressure to prepare ammonium or alkali metal borate solution. The following is the range in which ammonium dihydrogen borate reacts with Ca(NO ₃ ) ₂ and Ca(OH) ₂ and adjusts the pH with Ca(OH) ₂ to prepare a series of calcium borates:

60NH ₄ H ₂ BO ₃ ＋5Ca(NO ₃ ) ₂ ＋Ca(OH) ₂ →6Ca(B ₅ O ₈ ) ₂ nH ₂ O＋10NH ₄ NO ₃ ＋50NH ₄ OH＋(36-6n)H ₂ O, pH=5～6 ,

30NH ₄ H ₂ BO ₃ ＋4Ca(NO ₃ ) ₂ ＋Ca(OH) ₂ →5Ca(B ₆ O ₁₀ )·nH ₂ O＋8NH ₄ NO ₃ ＋22NH ₄ OH＋(20-5n)H ₂ O, pH=7～8,

20NH ₄ H _{2 BO 3} ＋4Ca(NO ₃ ) ₂ ＋Ca(OH) ₂ → _5CaB 4 O ₇ nH 2 O＋8NH ₄ NO ₃ ＋12NH ₄ OH＋(15-5n)H ₂ O, pH=8.2～9.3,

12NH ₄ H ₂ BO ₃ ＋3Ca(NO ₃ ) ₂ ＋Ca(OH) ₂ →2CaB ₆ O ₁₁ nH ₂ O＋6NH ₄ NO ₃ ＋6NH ₄ OH＋(10-n)H ₂ O, pH＝9.3～11.0,

6NH ₄ H ₂ BO ₃ ＋2Ca(NO ₃ ) ₂ ＋Ca(OH) _{2 →} 3CaB ₂ O 4 ·nH ₂ O＋4NH ₄ NO ₃ ＋2NH ₄ OH＋(6-3n)H ₂ O, pH≥11.0, also containing Na, K alkali metal borates can also react with calcium nitrate and calcium hydroxide to produce a series of calcium borates. The amount of Ca(NO ₃ ) ₂ and Ca(OH) ₂ added is 1-1.3 times of the reaction weight.

In the present invention, ammonium dihydrogen borate and borate or polyborate solutions of alkali metals can be obtained by leaching and demineralizing boron ore with _NH3 water and _CO2 gas. In this way, different proportions of NH ₃ and CO ₂ can be added according to the different boron content and magnesium (MgO) content in the ore, so that for some ores with low grade and high magnesium content, only need to increase the proportion of CO ₂ . In addition, NH ₃ and CO ₂ are used instead of (NH ₄ ) ₂ CO ₃ or NH ₄ HCO ₃ , so that the NH ₃ produced in the process of calcium production and calcium nitrate production does not need to be carbonized into (NH ₄ ) ₂ CO ₃ or NH ₄ HCO _3. It not only reduces the process, but also saves equipment investment. At the same time, when _NH3 and _CO2 are directly leached with ore, heat will be released, which can supplement the heat required for ore leaching, thereby reducing energy consumption. In the present invention, for hardness>4 containing Mg, Ca, Sr, Mn , Fe ore, when leaching, add triethanolamine or ethylenediamine to absorb CO ₂ , which can accelerate the leaching reaction. The addition amount of triethanolamine or ethylenediamine should be appropriate, the addition amount is too high, increases cost, is too low, and effect is not good. The borate or polyborate of dihydroammonium borate or alkali metal used in the present invention can be obtained from three major categories of 60 kinds of boron ores, as shown in Table 1.

Table 1

(1) Borate ore containing Mg, Ca, Sr, Mn, Fe

Hardness＞4

Boronite [Mg ₂ B ₂ O ₅ ·H ₂ O

or Mg ₂ [B ₂ O ₄ (OH)](OH)]

Fibrous boronite (MgB ₂ O ₄ ·H ₂ O),

Mg0.2B ₂ O ₃ 3/2H ₂ O, Mg ₃ [B ₅ O ₇ (OH) ₄ ] ₂ H ₂ O

Suianite, Suiborite, Monoclinic Magnesite

(Mg ₂ (B ₂ O ₅ )]

Magnesite[Mg ₃ (BO ₃ ) ₂ ]

Orthorhombite[Mg ₃ (BO ₃ ) ₂ ]

Werborite[Mg ₉ (H ₂ O)(BO ₃ ) ₂ (OH) ₁₂ ]

Carpenterite[Mg ₂ (CO ₃ )(HBO ₃ )·5H ₂ O]

Magnesite [Mg, Fe) ₂ Fe ³⁺ (BO ₃ )O ₂ ]

Uranium-bearing iron-boron ore (Wengquangou, Liaoning, China)

Boromanganese steerite[Ca ₆ Mg ₅ Mn(B ₂ O ₅ ) ₆ ]

Free boron manganese calcium magnesium stone

[Ca(Mn, Mg)[B ₂ O ₄ (OH)]OH]

Bormanite [Mg ₃ MnMn ₂ ³⁺ (BO ₃ ) ₂ )O ₄ ]

Acetolite[Ca ₄ Mn(BO ₃ ) ₃ (CO ₃ )O ₃ ]

Orthorhombite Mg ₃ Mn ₃ [BO ₃ ] ₂ O ₄

Mansoborite Mn ₃ [BO ₃ ] ₂

Hardness≤4

Zhang's boorite (Mg(H ₂ O)[B ₄ O ₅ (OH) ₄ ])

Pentahydrate (Mg ₂ (H ₂ O)[B ₄ O ₅ (OH) ₄ ] ₂ )

Alborite (Mg(H ₂ O)[B ₃ O ₄ (OH) ₂ ] ₂ )

Biornessite (Mg ₂ B ₁₂ O ₂₀ ·15H ₂ O)

Boronite (Mg(CH ₂ O) ₆ [B ₆ O ₉ (OH) ₂ ])

Pillarite (Mg(B ₂ O(OH) ₆ ] or MgB ₂ O ₄ 3H ₂ O)

Borrezite (Mg(H ₂ O) ₅ [B ₃ O ₃ (OH) ₅ ] or Mg ₂ B ₆ O ₁₁ ·15H ₂ O)

Boronite (Mg(H ₂ O) ₅ [B ₃ O ₃ (OH) ₅ ] or Mg ₂ B ₆ O ₁₁ ·15H ₂ O)

Strontium borite Sr ₂ B ₆ O ₁₁ ·4H ₂ O

Triclinoboronite Sr ₂ B ₁₁ O ₁₆ (OH) ₅ ·H ₂ O

Strontite (Sr ₂ (H ₂ O)[B ₅ O ₈ (OH)] ₂ [B(OH) ₃ ])

Sr ₂ (H ₂ O)B ₅ O ₈ (OH)] ₂ [B(OH) ₃

Monoclinic strontite SrB ₆ O ₁₀ dihydrate

Figure Boronite Sr(H ₂ O) ₃ [B ₆ O ₉ (OH) ₂ ]

Basic boronite CaSr(H ₂ O) ₅ [B ₁₄ O ₂₀ (OH) ₆ ]

Basic calcium strontite[(Ca.Sr) ₂ (H ₂ O) ₂ (B ₄ O ₅ (OH) ₄ ](B ₅ O ₆ (OH) ₄ ] ₂

Kurganda CaSr(BO ₂ ) ₄ ·H ₂ O

Strontium boronite (Ca, sr) ₂ Mg(B ₄ O ₆ (OH) ₂ ] ₃ 1.5H ₂ O

Mansoborite Mn ₃ (BO ₃ ) ₂

Boerolite Mn ₄ (B ₂ O ₅ )(OH) ₄

Boromangite Mn ₂ [B ₂ O ₄ (OH)](OH)

Hydroborite CaMg(H ₂ O) ₃ (B ₃ O ₃ (OH) ₃ ] ₂

Hemoborite CaMg(H ₂ O) ₆ (B ₃ O ₃ (OH) ₅ ] ₂

Carbunite Ca ₄ Mg[B ₂ O ₃ (OH) ₃ ] ₂ (CO ₃ ) ₂

Hydroborite MgCa ₂ (HCO ₃ ) ₂ (B(OH) ₄ ] ₂ (OH) ₂ ·2H ₂ O

Watt calcium magnesium boronite Ca ₅ MgB ₂₄ O ₄₂ 30H ₂ O

Hydropericlase CaMgB ₆ O ₁₁ 6H ₂ O

(2) Borate minerals containing Na, K, NH ₄ ⁺

Anhydrous Borax Na ₂ B ₄ O ₇

Orthorhombic borax Na ₂ B ₄ O ₇ ·4H ₂ O

Anhydrous Borax Na ₂ (H ₂ O) ₃ [B ₄ O ₆ (OH) ₂

Tripartite borax Na ₂ (H ₂ O) ₃ [B ₄ O ₅ (OH) ₄ ]

Natural Borax Na ₂ (H ₂ O) ₈ [B ₄ O ₅ (OH) ₄ ]

Boronite Na ₂ (H ₂ O) ₂ [B ₅ O ₇ (OH) ₃ ]

Boronite Na ₂ (H ₂ O)[B ₅ O ₆ (OH) ₅ ]

Boronite Na ₂ [B ₅ O ₆ (OH) ₅ ]

Alboronite Na ₂ (H ₂ O) ₂ [B ₃ O ₄ (OH) ₂ ] ₂

boronite Na ₂ (H ₂ O) ₃ [B ₅ O ₆ (OH) ₄ ]

Boronite NH ₄ [B ₅ O ₆ (OH) ₄ ]

Boramite NH ₄ (H ₂ O)[B ₅ O ₆ (OH) ₄ ]

Borkite K(H ₂ O) ₂ [B ₅ O ₆ (OH) ₄ ]

(3) Composite borate minerals containing alkali metals Na, K, NH ₄ ⁺ and alkaline earth metals Mg, Ca, Sr

Bischite Na ₆ Mg(H ₂ O) ₁₀ [B ₆ O ₇ (OH) ₆ ] ₄

Na ₂ Mg(H ₂ O) ₂ [B ₆ O ₉ (OH) ₂ ] ₂

Naborite NaCa(H ₂ O) ₆ [B ₅ O ₇ (OH) ₄ ]

or NaCaB ₅ O ₉ 8H ₂ O

Clinoborite NaCa(H ₂ O) ₃ [B ₅ O ₇ (OH) ₄ ]

KHMg ₂ (H ₂ O) ₄ [B ₆ O ₈ (OH) ₅ ] ₂ or

K ₂ 0.4Mg0.11B ₂ O ₃ 18H ₂ O

KMg ₂ B ₁₁ O ₁₉ 9H ₂ OK ₂

0.4Mg0.12B ₂ O ₃ 18H ₂ O

It can be seen from Table 1 that the 60 kinds of ores can be divided into three categories and four subcategories. According to different ores, the ore processing conditions are different. The technical process of the present invention is further described in detail below according to different ores. Fig. 1 is a process flow diagram of the present invention.

(1) For boron ore with hardness > 4 containing Mg, Ca, Sr, Mn, Fe.

Coarsely crush the boron raw material into pieces of 1-40 centimeters, grade them according to the size of the pieces, put them into the roasting kiln 1 and heat them to 620-950° C., and after 12-72 hours, finally control the reburning loss rate of the raw materials at 0.5-5%. The roasted raw materials are ground to a size of 160 mesh or more in the pulverizer 2 (including ball mill, rod mill, and suspension roller mill) and pass 95%. If boiling roasting is adopted, the powder is ground first and then roasted, the temperature is 750-1030°C, and the time is 0.5-1.5 hours.

Put the roasted and ground boron raw material into the mineralization tank 3, add ammonia and CO ₂ gas, the amount of ammonia added is NH ₃ : B ₂ O ₃ =1.1～1.3:1.0 (molar ratio), and the liquid-solid ratio is 1 : 2~3. The amount of CO ₂ to be added is 1 to 1.3 times the sum of the molar contents of MgO, CaO, SrO, MnO, and Mn ₂ O ₃ in the ore. Mineralization temperature ≥ 130°C, mineralization pressure 0.7-2.0MPa, mineralization time until the boron leaching rate reaches 73-85%. In order to make _CO2 react with the ore more completely, when the ore is demineralized, a _CO2 absorbent can be added, such as triethanolamine, ethylenediamine and other substances at 10-50 grams per liter. When the mineralization has reached the leaching rate, reduce the pressure to 0.2-0.4MPa immediately while it is hot, and press it into the filter press 4. When the filter press is full (when the filtrate no longer flows), use circulating washing water at 60 Wash three times at ~95°C, and finally wash once with hot water at 60~95°C to make the compatibility of _B2O3 in the filter residue ≤0.4%, then dry the filter cake with compressed air until the water content is 20~30% _, and discard it. The raw juice of the filtrate is ammonium dihydrogen borate, containing 30-120 grams/liter of B ₂ O ₃ , 20-40 grams/liter of NH ₃ , and 10-50 grams/liter of ethylenediamine or triethanolamine.

Add the filtrate raw juice to the calcification kettle 13, and add Ca(NO ₃ ) ₂ solution and Ca(OH) ₂ suspension according to B ₂ O ₃ :CaO=1.0:0.95～1.1 (molar ratio), Ca(NO ₃ ) The ratio of ₂ and Ca(OH) ₂ is from equimolar to 10% excess of Ca(OH) ₂ , the reaction temperature is 60-95°C for 1-3 hours, and then the pH is adjusted with Ca(OH) ₂ . Adjust to different pH values according to the preparation of different calcium borates, and adjust to the respective pH values according to the following different calcium borate products: Ca(B ₅ O ₈ ) ₂ ·nH ₂ O, adjust pH=5～6, CaB ₆ O ₁₀ Adjust pH _{= 7} ~ ₈ with nH _{2 O ;} adjust _pH with CaB _{4 O 7 ;} O to adjust the pH to >11.0, and Ca ₅ [B ₁₁ O ₁₉ ] ₂ ·nH ₂ O to adjust the pH to 9.0. Press the prepared calcium borate solution into the filter press 16 at 0.2-0.4 MPa. When the filter press liquid no longer flows, wash it three times with 60-95 ° C, 0.3-0.5 MPa circulating washing water, and 60-95 ° C hot water After washing once, the first washing water is sent to the calcium production process for dissolving NH ₄ NO ₃ . Ethylenediamine is recovered by distillation and condensation. When triethanolamine circulates concentration ≥ 110 g/L, the mother liquor after calcification circulates to mineralization 2. The recovery rate is 81-92%. The pressurized filter cake contains wet calcium borate with 50-70% water content. The wet calcium borate is sent to the drying process. Drying with a rotary dryer 17 or a microwave dryer can produce dry calcium borate with a moisture content≤1%. Not only the drying effect is good, but also the dust is not easy to take away.

Calcium nitrate Ca(NO ₃ ) ₂ in the calcification process is produced in the calcium nitrate kettle 6 with NH ₄ NO ₃ and CaO, and the calcium nitrate is then filtered with the filter press 9, and the filtrate is the calcium nitrate decalcification kettle 13. The ammonia released from the calcium-making kettle 6 is absorbed by the jet absorber 10 at a temperature of 30-50° C., and is circulated and absorbed until NH ₃ ≥ 18%, and then sent to the mineral decomposition kettle 3 as NH ₃ water.

5, 12, 14, and 15 are all pumps among Fig. 1, and 11 is an aqueous solution circulation tank.

(2) For boron raw materials containing Mg, Ca, Sr, Mn, Fe with hardness ≤ 4 (including boron ore, industrial products, chemicals).

The process of this kind of raw material is basically the same as the above process, only the following two points are different, the ore can be demineralized without roasting and directly grinding, the boron leaching rate is 76-94%, and no _CO2 adsorbent is added during demineralization.

(3) Boron raw materials containing sodium, potassium, and ammonium (including boron ore, industrial products, and chemicals).

The raw material is dissolved in water at 40-100°C, the solid-liquid ratio is 1:1.5-3.0, and then filtered, and the filtrate is the raw material for calcification. Other procedures and conditions are all the same as the process of (1). But this kind of raw material to product is different according to different ores, for the ore containing NH ₄ ⁺ , then its by-product is the same as (1) flow process, can return to the calcium production process, but for the ore containing Na, K respectively get NaNO ₃ and By-product of KNO ₃ , cannot be returned.

Na ₂ B ₄ O ₇ ·10H ₂ O＋3Ca(NO ₃ ) ₂ ＋Ca(OH) ₂ →Ca ₂ B ₆ O ₁₁ ·nH ₂ O＋6NaNO ₃ , pH=9.3～11.0, K ₂ B ₄ O ₇ ·10H ₂ O＋3Ca( NO ₃ ) ₂ +Ca(OH) ₂ →Ca ₂ B ₆ O ₁₁ ·nH ₂ O+6KNO ₃ , pH=9.3～11.0 If NaNO ₃ , the filtrate obtained in the filter press 16 can be sent to The evaporator 19 evaporates and concentrates, and the evaporation temperature is 123-125° C. until it reaches 47-50° Be′, and the specific gravity is 1.480-1.530, and the crystallization tank 20 is sent to cooling. Stir and cool to about room temperature, the sodium nitrate crystallizes out, dehydrate in the centrifuge 21, and finally dry in the dryer 22. If the by-product of KNO ₃ is produced, the evaporation end point is 45-48°Be′, the specific gravity is 1.450-1.495, the temperature is 118-120°C, and other conditions are the same as that of NaNO ₃ .

(4) For composite boron raw materials containing alkali metals Na, K, NH ₄ ⁺ and alkaline earth metals Mg, Ca, Sr. (including ores, industrial products, chemicals).

The production process of this type of ore is similar to (2), except that the temperature of ore decomposition is room temperature to 67°C and the reaction is stirred under normal pressure, and the boron leaching rate is 85 to 99%. Other conditions are the same as (2), and by-products are treated the same as (3).

In the present invention, the solid-liquid separation of calcium borate adopts a pressure filter (comprising horizontal plate type, plate frame type, box type, pressurized blade, continuous pressurized filter) or a press machine, which is compared with centrifugal, gravity, vacuum and other solid filters. Liquid separation has the following advantages: clear solid-liquid separation, less cracks in the filter cake, favorable for large-scale operation, small amount of washing water, low energy consumption, and boron recovery rate can be increased by 10-30%.

The invention adopts a rotary dryer or a microwave dryer to dry the wet calcium borate, so that the water content in the product can be reduced to 0.5-1%. Improved product quality.

The calcification still that the calcification process of the present invention adopts, its paddle apart from kettle wall≤10 centimeters, paddle is anchor type or frame type, and rotating speed is ≥24 rpm.

Example 1

All will use calcium nitrate solution when preparing calcium borate, so describe with embodiment 1 separately.

Take by weighing 1000 kilograms of ammonium nitrate, put into calcium-making kettle, contain CaO30.7 gram/liter after filtering, NO ' ₃ 55 gram/liter, the first wash water ² rice of procedure Dissolving ammonium nitrate. Stir and stir, Then weigh 654 kilograms of lime. At this time, it was an exothermic reaction, and a large amount of foam was generated. Add ash slowly, and naturally heat up to 70°C. Then heat the jacket to boiling, keep it at 102-108°C for 2 hours, pump it into the filter press while it is hot, the slurry pressure is 0.3MPa, when the filter press filtrate stops flowing, the solid material has been filled Filter press, stop filter press. Use 70°C 2M ³ circulating washing water for jacket washing three times, the pump pressure is 0.4MPa, and finally wash once with 3M ³ 70°C hot water, and finally analyze the NO′ ₃ in the washing water at 0.4 g/L.

At this time, a 1.8M ³ solution containing 170 g/L Ca(NO ₃ ) ₂ of CaO was prepared. The yield of NH ₄ NO ₃ is 94%.

The ammonia gas released from the calcium production reactor is absorbed by the jet absorber (venturi tube type) at a temperature of 30-50°C. When the NH ₃ 18% is absorbed continuously, the 1.2M ³ dilute ammonia water is sent to the mineral decomposition kettle for decompression. raw material.

Example 2

Prepare calcium nitrate solution process with embodiment 1. The calcium nitrate solution can continue to evaporate to 126-129°C, the specific gravity is 1.690-1.775 (59-63°Be′), and then the calcium nitrate crystal Ca(NO ₃ ) ₂ 4H ₂ crystallizes when it is cooled to 3°C higher than the cooling water temperature O1400 kg, purity ≥ 99%, can be solid, commercial sale.

Example 3

Grind the boromagnesite in a ball mill to 160 meshes and test that the _B2O3 content is 30.5%. Weigh ₂₀₀₀ kg and put _it into _the mineralization kettle for mineralization. 1.25M ³ of 20% dilute ammonia water is added, and 190HM ³ (standard state cubic meter) CO ₂ is passed through, and mineralized at 2.0MPa for 4 hours, ^and then heated in an 80m ² horizontal filter press to Pressure filtration under 0.3MPa. Obtain 89 g/L B ₂ O ₃ and filter stock solution 6.5M ³ to send to decalcification. The filter cake is washed three times with circulating water at 85°C and pumped at 0.35MPa pressure, and finally washed once with hot water at 85°C (0.35MPa) until the washing liquid contains 0.7 g/L of B ₂ O ₃ . Then, the filter cake was blown dry with filter air, and the filter residue was 320 kg, and 1.7% of residual B ₂ O ₃ was discarded.

Filter the stock solution and add it to the calcification kettle, add 170 g CaO/liter calcium nitrate solution 1.15M ³ , 120 g CaO/liter Ca(OH) ₂ suspension 0.405M ³ calcify at 85°C for 2.5 hours, then add Ca( OH) ₂ to adjust the pH to 9.0. After half an hour, press filter with a plate and frame filter press. The pressure of the pumped slurry is 0.3MPa. The filtrate and the first washing water are sent to make calcium nitrate. washing solution for three times, and finally wash once with pumped 85°C hot water at 0.4 MPa. The final NO ₃ ^- of the washing water is 0.5 g/L, and the amount of washing liquid is ^6M each time. The filter cake is CaB ₄ O ₇ ·4H ₂ O product. Containing 65% moisture, it is sent to a φ1.5×15m indirect heating rotary dryer, the temperature of the kiln head is 850°C, and the tail of the kiln is maintained at 80°C. The material stays in the machine for 10 minutes, and the water content of the output material is 0.5%, and then sent to the jet mill to be ground to 18 μ, and used as an amorphous superfine powder.

This embodiment is suitable for borate minerals, chemicals or industrial products containing Mg, Ca, Sr, Mn and Fe with a hardness of ≤4. The total yield of boron is generally 84-98%.

Example 4

2947 kilograms of B ₂ O ₃ 20.7% of the reservoir water boormagnese operation is the same as that of embodiment 3, only feed CO ₂ to increase to 280HM ³ , drop into 170 grams of CaO/litre 1.44M ³ calcium nitrate solution during calcification, 0.67M ³ 120 g CaO/L Ca(OH) ₂ suspension, adjust pH=10.5 with Ca(OH) ₂ to obtain Ca ₂ B ₆ O ₁₁ 5H ₂ O, containing B ₂ O ₃ 45.1% CaO ₂ 4.3% free H ₂ O10.5%, made into 0.5mm granular products by granulator.

Example 5

2000 kilograms of boronite (containing B ₂ O ₃ 30%), the process condition embodiment 3 is the same, only drop into 1.92M ³ , the calcium nitrate solution of 170 grams of CaO/liter during calcification, the calcium nitrate solution of 1.34M ³ 120 grams of CaO/liter The Ca(OH) ₂ suspension was adjusted to pH = 11.5 with Ca(OH) ₂ to prepare CaB ₂ O ₄ ·6H ₂ O containing 34.5% of B ₂ O ₃ and 28% of CaO.

Example 6

Use 2400 kilograms of boormangite (containing B ₂ O ₃ 25%), the operating conditions are the same as in Example 3, except CO ₂ is 235HM ³ , drop into 0.48M ³ calcium nitrate solution during calcification, 0.14M ³ Ca(OH) ₂ outside the suspension. Ca(B 5 O 8 ) ₂ · _{6H 2} O product containing 67% of B ₂ O ₃ and 10.5% of CaO _was obtained by adjusting pH=5.5 with Ca( _OH ) 2 .

Example 7

The raw materials and conditions are the same as those in Example 3, only 0.77M ³ Ca(NO ₃ ) ₂ solution and 0.27M ³ Ca(OH) ₂ suspension are put in during calcification, and the pH=7.5 is adjusted with Ca(OH) ₂ to obtain A Ca(B ₆ O ₁₀ )·4H ₂ O product containing 61.2% of B ₂ O ₃ and 16.2% of CaO.

Example 8

Sodium borate containing 38.5% B ₂ O ₂ is ground to 160 mesh in a ball mill and weighed 2500 kg to contain B ₂ O ₃ 6.8 g/L HN ³ 24 g/L, Na ₂ O 3.5 g/L 4.8M ³ cycle first washing water, add 1300 kg of 20% dilute ammonia water, put them into the mineralization kettle together, stir and mix, and then feed 180HM ³ CO ₂ to react for 4 hours under normal pressure at 60°C: NaCa (H ₂ O) ₆ [B ₅ O ₇ (OH) ₄ ] ₂ ＋NH ₃ ＋CO ₂ →CaCO ₃ ↓＋＋[B ₅ O ₇ (OH) ₄ ]＋2NH ₄ ⁺ Na ⁺ was filtered by chamber filter press, The operating pressure of the slurry is 0.2 MPa, and the filtered stock solution with a B ₂ O ₃ content of 162 g/L is obtained. The filter residue is then washed with 4.8M ³ of circulating water at 60°C three times with a pump at 0.3MPa, and then washed once with hot water at 60°C and 0.4MP pressure until the washing water contains 0.85 g/L of B ₂ O ₃ .

Then, Ca(NO ₃ ) ₂ solution 3.04M ³ with 200 g/L CaO and 2.5M ³ suspension containing 120 g CaO/L Ca(OH) ₂ were slowly added to the ammonium borate solution for 2 hours of reaction. 2[B ₅ O ₇ (OH) ₄ ]＋2Na ⁺ ＋4NH ₄ ⁺ ＋2Ca(NO ₃ ) ₂ ＋Ca(OH) ₂ →Ca ₃ [B ₅ O ₇ (OH) ₄ ] ₂ nH ₂ O＋2NaNO ₃ ＋2NH ₄ O ₃ + 2NH ₄ OH was adjusted to pH 10.6 with Ca(OH) ₂ and reacted for another 0.5 hours. The slurry is pumped into a TN type countercurrent top-blown filter press with a pump pressure of 0.25 MPa, and the obtained filtrate contains 0.5 g/L Na ₂ O 2 and 36 g/L NH ₃ . Heat this solution in the evaporator to 121°C, the specific gravity is 1.42, put it in the cooling crystallization kettle and cool it until the temperature of the cooling water is 3°C higher than that of the cooling water. NaNO ₃ is separated off in a centrifugal separator. Wet _NaNO3 was dried at 112°C in an airflow dryer to obtain sodium nitrate with a purity of 99%. And containing NO' ₃ 82 g/liter solution containing ammonium nitrate is sent to make calcium nitrate.

The calcium borate filter cake after the calcification is washed three times with pump water washing 0.35MPa pressure cycle, 60 ℃ hot water 0.40MPa washes once until the NO' ₃ content is 1.0 g/liter. The amount of washing water is 5.0M ³ each time. Calcium borate containing 60% water was dried in a 5780 MHz microwave drier for 30 minutes at a temperature of 85°C. Grind to 120-200 mesh with a hammer mill. The product is Ca ₃ [B ₅ O ₇ (OH) ₄ ] ₂ ·2H ₂ O containing B ₂ O ₃ 50.1% CaO2 4.3%. The total yield of boron is 93.6%.

Example 9

The conditions are the same as in Example 8, only 200 grams of CaO/liter Ca(NO ₃ ) ₂ solution 1.97M ³ is added during calcification, and 120 grams of CaO/liter Ca(OH) ₂ 1.08M ³ is added to obtain B ₂ O ₃ 50.8% CaO 27.1% Ca ₂ B ₆ O ₁₁ ·5H ₂ O product.

Examples 8 and 9 are suitable for borate minerals containing not only Na, K, NH ₄ ⁺ but also Ca, Mg, Sr, Mn, and Fe elements. Such as boronite, boronite, clinoborite and so on.

Example 10

Grind boron potassium magnesium stone to 160 mesh, 3000 kg of ore powder with 30.6% B ₂ O ₃ in the laboratory is put into the mineral decomposition kettle to contain B ₂ O ₃ 9 g/L, K ₂ O 5.1 g/L, NH ₄ ⁺ Add 20 g/L of ore de-washing water 5M ³ , then add 1030 kg of dilute ammonia water with 20% NH ₃ , feed 68HM ³ CO ₂ , react at 65°C for 4 hours under normal pressure: KMg ₂ B ₁₁ O ₁₉ ·9H ₂ O＋4NH ₃ ＋2CO ₂ →K ⁺ ＋[B ₁₁ O ₁₉ ]″″′＋2MgCO ₃ ＋4NH ⁺

Solid-liquid separation, washing, and calcification were the same as in Example 8. After calcification, the pH was adjusted to 9.0 with NH ₄ OH. The by-product KNO ₃ was evaporated to 119°C, 46.5°Be′, cooling and crystallization was the same as in Examples 8 and 9, and 220 kg of KNO ₃ with a purity of 99% was obtained. The product is Ca ₅ [B ₁₁ O ₁₉ ] ₂ ·16H ₂ O containing B ₂ O ₃ 52/1%, CaO 22%, and the total yield of boron is 90.5%.

Example 11

The uranium-containing iron-boron ore with a hardness of 5.5 is roasted at 900° C. for 30 hours in the roasting kiln 1 with 3600 kg of ore in Wengquangou Mine, Liaoning, China, and the reburning loss rate is controlled to be 3%, which is the best. Ball mill 2 grinds to 160 mesh.

Add 3,000 kg of ore powder into the mineral solution kettle 3, test B ₂ O ₃ 8.0%, MgO 45%, CaO 13%, SiO ₂ 12%, Fe ₂ O ₃ 17%, Al ₂ O ₃ 5%, containing U ₃ O 80. 03%. First calculate and deduct 12.1% of MgO with Mg ₆ [Si ₄ O ₁₀ ](OH) ₈ , the remaining 32.9% and 13% of CaO require excess CO ₂ 31.44×1.3=40.88 kg molecules. Fe ₂ O ₃ (including Fe ⁺⁺ ), Al ₂ O ₃ and U ₃ O ₈ are precipitated with their corresponding hydroxides, so they are not considered in the calculation. Drop into 770 kilograms of 20% ammoniacal liquor, drop into 280 kilograms of ethylenediamine (comprising circulation amount) simultaneously. Soak the ore powder with ammonia water and ethylenediamine solution first, stir and react, and introduce CO ₂ 916HM ³ . Naturally raise the temperature to about 60°C, then turn on the steam to raise the temperature to 140±5°C, pressure 2.0MPa, stir and react for 6 hours, and then discharge. The boron decomposition rate of the slurry sample was tested to be 75%. 5M ³ containing B ₂ O ₃ 38 g/L ore solution is put into the calcification kettle, add 153 g CaO/L Ca(OH) ₂ suspension 0.1 m, 200 g CaO/L Ca(NO ₃ ) ₂ solution 0.31 m ³ Calcify at 80°C for 2 hours, adjust the pH to 9.2 with Ca(OH) ₂ , and react for another 1 hour.

Other operations are the same as Example 3. This example makes B ₂ O ₃ 45% CaO2 2.5% such as U ₃ O ₈ 5ppb in the finished product containing uranium, iron and boron raw materials, and 430 kg of products of CaB ₄ O ₇ ·6H ₂ O. Ethylenediamine is recovered in the form of washing water after calcification, and the recycling yield is 82.5%. Most of U ₃ O ₈ remains in the slag, which does not affect the further extraction of uranium.

This example is applicable to boron ores with B ₂ O ₃ ≥ 7% and hardness > 4, such as boronite, fibrous boronite, suianite, magnesium boronite, mansnite, etc.

Example 12

The boronite-boronite (Mg, Fe) ₂ Fe ³⁺ [BO ₃ ]O ₂ ore was crushed to ≤3 mm grains, sent to the fluidized roasting kiln 1 by a fan and roasted at 750°C for 45 minutes, measured The loss on ignition rate is 1.1%. Then grind to 160 mesh and pass through 95% sieve.

Contain B ₂ O ₃ 6.8 grams/liter NH ₃ 21 grams/liter, ethylenediamine 50 grams/liter washing water 6.5M ³ drop in the mineral solution kettle 3, drop into 3000 kilograms of ore powder again, 650 kilograms of 24% ammoniacal liquor, pass Add CO ₂ 730HM ³ , heat up and keep the highest temperature at 143°C, and the pressure at this time is 147MPa, and stir for 7 hours. The temperature dropped to 135°C, the pressure was 0.78MPa, and the boron leaching rate was 84.3%. When the pressure is slowly released to 0.38MPa, the slurry is put into the TN filter press 4, and the filtrate ^5.8M3 containing B ₂ O ₃ 36 g/L and ethylenediamine 48.8 g/L is filtered and sent to decalcify. The filter residue was washed three times with pump 5 pressure 80°C 6.5M ³ circulating washing liquid, and washed once with 80°C hot water. The first washing liquid is sent to soak mineral powder.

Mineralization and filtration mother liquor is sent in the calcification still 13, adds and contains 202 grams of CaO/ liters Ca(NO ₃ ) ₂ solution 556 liters, and 140 gram CaO/ liters of lime emulsion 403 liters, calcification reaction 2.5 hours, adjust with lime emulsion again pH = 11.5, and reacted for another 0.5 hour. The stirred reaction was carried out at room temperature. Pump 14 uses 0.2MPa pressure filtration, and the filter press adopts TN filter press 16 filtrate 5.6M ³ to send to the process of removing ethylenediamine by distillation. The filter cake is then washed three times with hot water at 60°C by pump 15 and once with hot water at 60°C. The volume of each wash is 5.5M ³ . Finally, blow dry with 0.6MPa compressed air for three minutes. The wet calcium borate containing 60.5% water is then sent to the spin flash dryer for drying, the drying temperature is 167°C at the highest point and 85°C at the lowest point.

5.6M ³ containing ethylenediamine 47.8 g/L containing B ₂ O ₃ 6.8 g/L containing NH ₃ 25 g/L solution is sent to the distillation condensing tower. The steam in the lower part of the tower is indirectly heated, the heating temperature is 132°C, ethylenediamine and ammonia are distilled at the same time, the cooler in the upper part of the tower, the water inlet temperature of the condenser is 12°C, the water outlet temperature is 32°C, ethylenediamine and ammonia are condensed together, and the ethyl The diamine solution is condensed, and the washing water after mineralization is used to directly absorb ethylenediamine and ammonia. The amount of washing water used is 6M ³ . 10 kg was made into a solution of about 50 g/L for demineralization. The ammonium nitrate solution at the bottom of the distillation tank is sent to make calcium nitrate.

The finished product is 588 kg of calcium borate, containing _{B2O3 35.1} % _CaO2 8.3% _CaB2O4 · _{4H2O .}

This embodiment can also be applied to boronite, fiber boronite, suianite, magnesium boronite, orthorhombessite, Wei boronite, boronite, boronite, boronite, and boronite. Magnesite, boromanganite, aorthite, orthorhombite, manganite, etc. The boron leaching rate is generally between 73-85%, and the yield is 71-83%.

Example 13

2000 kg of water boronite with 38% B ₂ O ₃ is ground to 160 mesh by a suspension disc mill, and the first ore dewashing with 8 g of B ₂ O ₃ /L and 30 g of NH ₃ /L is added Water 5.4M ³ into the mineral solution kettle, soak and stir evenly. Then put 2.2M ³ of 24% ammonia water into the ammonia synthesis system, feed CO ₂ at 0.8MPa to 50m ³ , raise the temperature to 135°C with jacket steam, and react for 4 hours. Then it is pressed into a BMY-100080m ² plate and frame filter press with a pressure of 0.35MPa, and the filtrate contains 89 g/L 7.0M ³ of B ₂ O ₃ and is sent for decalcification. Use a pump to wash three times with 0.42MPa pressure and 87°C circulating washing water, each washing water is 5M ³ , and then wash once with 87 hot water, and the B ₂ O ₃ in the washing water is 0.8 g/L.

Filter the stock solution, sprinkle 7.2 kg of calcium hexaborate seed crystals into the calcification kettle, stir evenly, and control the number of revolutions at 24 rpm, then add Ca(NO ₃ ) ₂ 2M ³ containing 154 g/L CaO, 110 g CaO/L The Ca(OH) ₂ suspension of 0.93M ³ was slowly calcified for 3 hours, the temperature was controlled at 58-60°C, the pH was adjusted to 10.7 with Ca(OH) ₂ , and the reaction was continued for 1 hour. After calcification, filter with a filter press, and dry with the same embodiment 3. This example makes calcium hexaborate crystal 50.8% B ₂ O ₃ , CaO 27.3% 1188 kg.

Example 14

Weigh 2,000 kg of 30% B ₂ O ₃ natural boron yarn, put washing water 6M ³ in an ordinary stirred reactor and heat to 85°C, filter and remove the silt, and dissolve the natural borax in the silt washing water circulation. Add the corresponding NaOH. (Boramite, hydroboronite plus NH ₄ OH, hydroboronite plus KOH (to make filtration easier) to adjust the pH = 9.3. The filter residue was washed with water until B ₂ O ₃ 1 g/L. After filtration, the solution B ₂ O ₃ 98 g/L, put into the calcification kettle, slowly add Ca(NO ₃ ) ₂ 1.15M ³ , 0.4M ³ 120 g/CaO/L Ca(OH) ₂ suspension at temperature 85 Calcify at ℃ for 2.5 hours, adjust pH to 9.3 with Ca(OH) ₂ , and react for 0.5 hours. Separation of solid and liquid, drying as in Example 3, to obtain 1140 kg of B ₂ O ₃ 50.5% CaB ₄ O ₇ ·4H _{2 O.} The by-product sodium nitrate with a purity of 99% is 730 kg.

Example 15

With the feed liquid after filtration with embodiment 14, add the calcium nitrate solution of 1.44M ³ 170 g/liter CaO, the Ca(OH) ₂ 0.67M ³ of 120 g/liter CaO, carry out calcification reaction, Na ₂ B ₄ O ₇ +3Ca(N) ₃ ) ₂ +Ca(OH) ₂ →Ca ₂ B ₆ O ₁₁ ·nH ₂ O+6NaNO ₃ pH=10.1. The following other operations are also the same as in Example 14.

Prepare 1140 kg of dicalcium hexaborate containing B ₂ O ₃ 50.5% CaO27, 3%. Simultaneously, 730 kg of by-product sodium nitrate has a purity of 99%.

Example 16

Weigh 2000 kg of 30% B ₂ O ₃ boronite, and its operation is the same as in Example 13. Ca ₂ B ₆ O ₁₁ ·4H ₂ O is produced.

The by-product ammonium nitrate is 701 kg, which can be used as a recycled raw material for calcium nitrate production. Or wash once with 6M ¹³ circulating washing water at 65°C to produce a special product containing 6.0% NH ₄ NO ₃ , 45.0% B ₂ O ₃ 26% CaO, which is used as a high-temperature molten boron-containing material.

Embodiment 15, 16 is also applicable to all various boron ores, chemicals, and industrial products except those containing Na and K.

Embodiment 14, 15, 16 is applicable to Na, K, NH ₄ Borate minerals, industrial products, chemicals. Such as anhydrous, orthorhombic, anhydrous, triangular, natural borax, Italian, Nai, tetrahydric, polyhydric, boronite, boronite, boronite, boronite, etc.

Example 17

Grind manganese boronite to 160 mesh in a suspension roller disc mill, put 2000 kg of ore powder containing 20.7% B ₂ O ₃ into the ore decomposition kettle, so as to contain 8 g/L B ₂ O ₃ 21 g/L Soak in 3.0M ³ of NH ₃ demineralization washing water for the first time, and then add 20% ammonia water 2M ³ into it. When _CO2 reaches 0.7MPa, stop adding, heat up to 140±5°C, stir and react for 4 hours, and the decomposition rate of _B2O3 is 86%. When _the pressure is released to 0.80MPa, press into the filter press ( 80m ² , blade pressurized filter), and then washed three times with 0.40MPa 84°C circulating washing water, each time about 3M ³ and then washed once with 84°C hot water, and the filtered stock solution contained 76. g/L of B ₂ O ₃ ,

Raise the temperature to 60°C, slowly put 0.91M ³ solution containing 180g/L Ca(NO ₃ ) ₂ into the calcification kettle, then add 0.53M ³ 140g CaO/L Ca(OH) ₂ solution, and calcify for 1.5 hours. Adjust pH=10.5 with Ca(OH) ₂ . Pumped into the XMG60/800-X60m ² compartment filter press with a pump of 0.4MPa to filter, and then washed once with a pump of 0.5MPa at a pressure of 88°C and 4.4M ³ , and the wet finished calcium borate was dried by a 2450 MHz microwave dryer until it contained B ₂ O ₃ 45%, CaO ₂ 7% NH ₄ NO ₃ 6.8% special chemicals (for high temperature boron-containing processing industries such as glass industry) Ca ₂ B ₆ O ₁₁ ·5H ₂ O.

This embodiment is also applicable to chemicals and industrial products composed of magnesium, calcium, strontium, manganese and iron, and minerals with a hardness of ≤4, such as boromanite and boromanite.

Example 18

1000 kg 160 mesh containing B ₂ O ₃ 20.3% strontium boronite ore powder, add 3M ³ containing NH ₃ 30 g/l, B ₂ O ₃ 8.4 g/l ore washing water, add 22.8% NH ₃ water 2.48M ³ Put into the ore decomposition kettle, feed CO ₂ 140HM ³ , the pressure reaches 0.9MPa, slowly raise the temperature to 135°C, and stir for 4 hours. Demineralization, calcification process operation is the same as embodiment 3.

In this example, Ca ₂ B ₆ O ₁₁ ·5H ₂ O containing 50.5% B ₂ O ₃ CaO 26.8%.

This embodiment is also applicable to boronite, triclinic boronite, boronite, dihydrate monoclinic boronite, boronite, basic boronite, basic boronite, Similar minerals, industrial products and chemicals such as Kurganda Stone. The total yield of such boron is 81-89%.

Claims (10)

1. A method for preparing calcium borate ACaO EB ₂ O ₃ nH ₂ O (A=1～5, F=1～11, n=0～20) from boron ore, it is characterized in that from boron ore The borate solution obtained by leaching is simultaneously calcified with calcium nitrate Ca(NO ₃ ) ₂ and calcium hydroxide (Ca(OH) ₂ ), and then adjusted to pH with calcium hydroxide Ca(OH) ₂ or NH ₄ OH and KOH For the corresponding value of calcium borate to be prepared, the amount of calcium nitrate and calcium hydroxide added is 1-1.3 times the equivalent molar number according to the reaction formula, and Ca(B ₅ O ₈ ) ₂ ·nH ₂ O is prepared, pH=5-6 , Ca(B ₆ O ₁₀ ) nH ₂ O to adjust the pH to 7-8, CaB ₄ O ₇ nH ₂ O to adjust the pH to 8.2-9.3, Ca5(B ₁₁ O ₁₉ ) ₂ nH ₂ O, the pH to 9.0 , prepare Ca ₂ B ₆ O ₁₁ nH ₂ O to adjust pH to 9.3~11.0, Ca ₃ (B ₅ O ₇ (OH) ₄ ) nH ₂ Oph to 10.6, prepare CaB ₂ O ₄ nH ₂ O to adjust pH≥ 11.0, Ca ₅ (B ₁₁ O ₁₉ ) ₂ nH ₂ O to adjust the pH to 9.0, the obtained calcium borate is filtered and dried to obtain the product, the calcification temperature is room temperature to 95°C, and the borate solution is ammonium, potassium, Sodium salts. 2. preparation method as claimed in claim 1, it is characterized in that the borate solution that is leached from ore is after the boron ore that contains Mg, Ca, So, Mn, Fe of hardness > 4 is roasted, ground It is obtained by leaching ore dissociation with NH ₃ water and CO ₂ , ethylenediamine or triethanolamine. The amount of ammonia added is NH ₃ : B ₂ O ₃ =1.1～1.3:1.0 (molar ratio), and the solid-liquid ratio is 1:2 ~3, the amount of CO ₂ added is 1~1.3 times of the sum of moles of MgO, CaO, MnO, Mn ₂ O ₃ , and SrO, the amount of ethylenediamine or triethanolamine added is 10~50 g/L, and the mineralization temperature ≥130°C, the leaching pressure is 0.7-2.0MPa, and the boron leaching rate reaches 73-85% within the mineralization time. 3. preparation method as claimed in claim 1, it is characterized in that the borate solution obtained from ore demineralization is used ammoniacal liquor and It is obtained by CO ₂ leaching and mineralization. The amount of ammonia added is NH ₃ : B ₂ O ₃ =1.1~1.3:1.0 (molar ratio), the solid-liquid ratio is 1:2~3.0, and the amount of CO ₂ added is MgO, The content of CaO, MnO, Mn ₂ O ₃ , and SrO is 1 to 1.3 times (molar ratio), the mineralization temperature is ≥130°C, the mineralization pressure is 0.7 to 2.0MPa, and the leaching time is based on the boron leaching rate of 76~ 94% so far. 4. preparation method as claimed in claim 1 is characterized in that the borate solution obtained from ore demineralization is made of boron raw material (comprising boron ore, industrial products, chemicals) containing sodium, potassium, ammonium with 40～ Dissolved in water at 100°C, the solid-to-liquid ratio is 1:1.5-30 (weight ratio). 5. The preparation method as claimed in claim 1, characterized in that the borate solution obtained from the ore is composed of alkali metals Na, K, NH ₄ ⁺ , and alkaline earth metals Mg, Ca, Sr. The type boron ore is obtained by leaching and demineralizing with ammonia water and CO ₂ after grinding. The amount of ammonia added is NH ₃ : B ₂ O ₃ =1.1～1.3:1.0 (molar ratio), and the solid-liquid ratio is 1:2～3.0 , the amount of CO ₂ added is 1 to 1.3 times (molar ratio) of the sum of the contents of MgO, CaO, MnO, Mn ₂ O ₃ , and SrO in the ore. Take the time until the boron leaching rate reaches 85-99%. 6. preparation method as claimed in claim 1 is characterized in that calcium nitrate is made by the reaction of CaO and ammonium nitrate, and reaction by-product _NH water absorption is returned to mineral solution and made mineral solution. 7. preparation method as claimed in claim 1 is characterized in that the calcium borate suspension that calcification operation makes is filtered with pressurized filter press to get wet calcium borate. 8. preparation method as claimed in claim 7 is characterized in that through the wet calcium borate that filters is dried with rotary drier or microwave drier, adopts rotary flash drier to also can dries. 9. The preparation method as claimed in claim 6, characterized in that the NH water absorption is a jet absorption Venturi injector or a high-level ammonia absorption. _10. The preparation method according to claim 1 _, characterized in that it can prepare various kinds _of The series of calcium borates can be either crystalline or amorphous ultra-fine powder.

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