SU899473A1

SU899473A1 - Process for producing cryolite

Info

Publication number: SU899473A1
Application number: SU802922997A
Authority: SU
Inventors: Анатолий Семенович Коробицын; Адольф Макарович Загудаев; Татьяна Александровна Пермякова; Владимир Петрович Кондаков; Николай Васильевич Троян; Евгений Алексеевич Бураков; Борис Вениаминович Левитан
Original assignee: Предприятие П/Я А-7125
Priority date: 1980-05-12
Filing date: 1980-05-12
Publication date: 1982-01-23

Description

Изобретение относится к химической промышленности и может быть использовано при получении криолита.The invention relates to the chemical industry and can be used to obtain cryolite.

Известен способ получения криолита, включающий растворениё гидроокиси алюминия в плавиковой кислоте, а затем обработку полученного раствора содовым раствором и отделение полученного осадка [1].A known method of producing cryolite, including the dissolution of aluminum hydroxide in hydrofluoric acid, and then processing the resulting solution with a soda solution and separating the obtained precipitate [1].

Недостатком способа является то, что полученный криолит загрязнен кремнеземом, окисью натрия и окисью железа, которые вносятся вместе с гидроокисью алюминия.The disadvantage of this method is that the resulting cryolite is contaminated with silica, sodium oxide and iron oxide, which are introduced together with aluminum hydroxide.

Наиболее близким к предлагаемому. ₍$ по технической сущности и достигаемой цели является способ получения криолита, включающий смешение суспензии кристаллического фтористого натрия и перенасыщенного раствора фто- го ристого алюминия L2J.Closest to the proposed. ₍ $ according to the technical nature and the achieved goal, is a method for producing cryolite, which involves mixing a suspension of crystalline sodium fluoride and a supersaturated solution of fluoride aluminum L2J.

Однако использование кремнеземсодержащего кристаллического фтористого натрия в реакции с перенасыщенным раствором фтористого алюминия вызывает снижение выхода фтора в продукт ( ~50 - 55%) за счет образования кремнефтористоводородной кислоты и растворимого кремнефтористого натрия, которые выводятся из процесса с маточным раствором.However, the use of silica-containing crystalline sodium fluoride in a reaction with a supersaturated solution of aluminum fluoride causes a decrease in the fluorine yield in the product (~ 50 - 55%) due to the formation of hydrofluoric acid and soluble sodium silicofluoride, which are removed from the mother liquor process.

Цель изобретения - повышение выхода фтора в продукт при использований кристаллического фтористого натрия с весовым соотношением фтористого натрия к двуокиси кремния 0,25~ 0,49.The purpose of the invention is to increase the yield of fluorine in the product when using crystalline sodium fluoride with a weight ratio of sodium fluoride to silicon dioxide of 0.25 ~ 0.49.

Поставленная цель достигается способом, включающим смешение суспензии кристаллического фтористого натрия и пересыщенного раствора фтористого алюминия, смешение осуществляют в присутствии сернокислого алюминия в количестве 0,1-1,5 вес.%.The goal is achieved by a method comprising mixing a suspension of crystalline sodium fluoride and a supersaturated solution of aluminum fluoride, the mixture is carried out in the presence of aluminum sulfate in an amount of 0.1-1.5 wt.%.

П р и м е pl. 1000 кг кристаллического фтористого натрия, содержащего 20% NaF и 80% Si0_а (весовое отношение NaF : S10,- 0,25), смешипересыщеналюминия, добавляют вают с 5333,3 кг 3%-ного ного раствора фтористого в который предварительно сернокислый алюминий до достижения содержания 1,5% (или эквивалентное количество серной кислоты и гидроокиси алюминия). Процесс взаимодействия проводят при 80-90°С в течение 0,5*1 ч. После разделения суспензии фильтрованием получают 1657,1 кг влажного осадка и 4756,1 кг маточного раствора, содержащего 0,66% Na, 0,02% А 1, 0,4% F, 0,21% S i 0* . Влажт <ный осадок сушат. После сушки продукт содержит 4»88% Na, 5,55% Al, 15,8% F, 69,57% Si0_a. выход фтора в продукт составляет 90,44%.PRI me pl. 1000 kg of crystalline sodium fluoride containing 20% NaF and 80% Si0 _a (weight ratio NaF: S10, - 0.25), a mixture of supersaturated aluminum, is added with 5333.3 kg of a 3% solution of fluoride in which pre-aluminum sulfate to achieve a content of 1.5% (or an equivalent amount of sulfuric acid and aluminum hydroxide). The interaction process is carried out at 80-90 ° C for 0.5 * 1 h. After separation of the suspension by filtration, 1657.1 kg of wet cake and 4756.1 kg of the mother liquor containing 0.66% Na, 0.02% A 1 are obtained , 0.4% F, 0.21% S i 0 *. The wet cake is dried. After drying, the product contains 4 »88% Na, 5.55% Al, 15.8% F, 69.57% Si0 _a . the fluorine yield in the product is 90.44%.

Пример 2. 1000 кг кристалли10Example 2. 1000 kg of crystal 10

899473 4 ние NaF : Si0_г = 49), смешивают с899473 4 NaF: Si0 _g = 49), mixed with

26133,3 кг 3%-ного раствора фтористого алюминия, в который добавляют сернокислый алюминий до достижения содержания 0,1% (или эквивалентное количество серной кислоты и гидроокиси алюминия). Процесс взаимодействия проводят при 80-90 С в течение 0,5 1 ч. После разделения суспензии фильтрованием получают 2548,6 кг влажного осадка и 23584,7 кг маточного раствора с содержанием фтора 0,6%. |После сушки осадок содержит 52,62% F, 14,08% Al, 30,1% Na. Выход фтора в продукт составляет 85,49%.26,133.3 kg of a 3% solution of aluminum fluoride, to which aluminum sulfate is added until a content of 0.1% is reached (or an equivalent amount of sulfuric acid and aluminum hydroxide). The interaction process is carried out at 80-90 C for 0.5 1 h. After separation of the suspension by filtration, 2548.6 kg of wet cake and 23584.7 kg of mother liquor with a fluorine content of 0.6% are obtained. | After drying, the precipitate contains 52.62% F, 14.08% Al, 30.1% Na. The fluorine yield in the product is 85.49%.

Ожидаемый экономический эффект составит 1,5 млн.руб. в год.The expected economic effect will be 1.5 million rubles. in year.

ческого фтористого натрия, содержащего 75% Na и 25/ Si0_a ( весовое отношение NaF : Si0₂ = 3)«смешивают с 25000 кг пересыщенного 3%-ного раствора фтористого алюминия, в который предварительно добавляют сернокислый алюминий до достижения содержания 0,75% (или эквивалентное количество серной кислоты и гидроокиси алюминия).Процесс взаимодействия проводят при 80-90 С в течение 0,5-1 ч. После разделения суспензии фильтрова- 50 нием получают 2500 кг влажного осадка и 23687,5 кг мрточного раствора, содержащего 0,53% Na. 0,6% F, 0,31% SiC^, 0,02% Al. Осадок после сушки содержит 19,04% Na, 47,16% F, 11,79% SiO₂, 35 17,75^ Al. Выход фтора в продукт составляет 83,24%.sodium fluoride containing 75% Na and 25 / Si0 _a (weight ratio NaF: Si0 ₂ = 3) “is mixed with 25,000 kg of a supersaturated 3% solution of aluminum fluoride, to which aluminum sulfate is preliminarily added to reach 0.75% (or an equivalent amount of sulfuric acid and aluminum hydroxide). The interaction process is carried out at 80-90 C for 0.5-1 hours. After separation of the suspension by filtering, 5050 kg of wet sediment and 23687.5 kg of an inert solution containing 0 are obtained. , 53% Na. 0.6% F, 0.31% SiC ^, 0.02% Al. The precipitate after drying contains 19.04% Na, 47.16% F, 11.79% SiO ₂ , 35 17.75 ^ Al. The fluorine yield in the product is 83.24%.

Пример 3- 1000 кг кристаллического фтористого натрия, содержащего 98% NaF и 2% SiO_a (весовое отноше-40Example 3-1000 kg of crystalline sodium fluoride containing 98% NaF and 2% SiO _a (weight ratio 40

Claims

The invention relates to the chemical industry and can be used in the preparation of cryolite. A known method of producing cryolite involves dissolving aluminum hydroxide in hydrofluoric acid, and then treating the resulting solution with a soda solution and separating the resulting precipitate tl. The disadvantage of this method is that the resulting cryolite is contaminated with silica, sodium oxide and iron oxide, which are introduced together with aluminum hydroxide. Closest to the proposed, technical essence and achievable goal is a method for the production of cryolite, comprising mixing a suspension of crystalline sodium fluoride and a supersaturated solution of aluminum fluoride L2J. However, the use of silica-containing crystalline sodium fluoride in the reaction with a supersaturated solution of aluminum fluoride causes a decrease in the yield of fluorine in the product (50-55) for the formation of hydrofluoric acid and soluble sodium fluoride, which are removed from the mother liquor process. The purpose of the invention is to increase the yield of fluorine in the product when using crystalline sodium fluoride with a weight ratio of sodium fluoride to silicon dioxide of 0.250, 49. The goal is achieved by the method of mixing the suspension of crystalline sodium fluoride and the supersaturated solution of fluoride al 10 "" ne, mixing is carried out in the presence of aluminum sulphate in a quantity of 0.1-1.5 wt.%. Example 6 p 1. 1000 kg of crystalline sodium fluoride containing 20% NaF and 80 SiOg (weight ratio MaP: SJO, - 0.25) is mixed with 5333.3 kg 3 -saturated supersaturated solution of aluminum fluoride, in which aluminum sulfate is preliminarily added to reach a content of 1.5 (or equivalent amounts of sulfuric acid and aluminum hydroxide). The interaction process is carried out at 80-90 ° C for 0 hours. After separating the suspension by filtration, 1b57.1 kg of wet sediment and i756.1 kg of stock solution containing 0.66 Na, 0 ,, Q, k% F, 0 are obtained. , 2U SiO.,. The wet cake is dried. After drying, the product contains Na, 5.55% AB 15.8% F 69.57% Fluorine fluoride product is 90%. Example 2, 1000 kg of crystalline sodium fluoride containing 75% Na and 25 / Si Od (weight ratio NaF: SiO, 3), mixed with 25,000 kg of a supersaturated 3% aqueous solution of aluminum fluoride, to which aluminum sulphate is previously added to achieve a content of 0.75% (or an equivalent amount of sulfuric acid and aluminum hydroxide). t at 80-90 ° C for 0.5-1 h. After separating the suspension by filtration, 2500 kg of wet o adka and 23,687.5 kg mother liquor containing 0,53% Na solution. 0.6% F, 0.31% Si 0.02% A, The precipitate after drying is 19, OU Na,, l67pF, Ib S oSiOj, 17.75% A1. The fluorine yield to the product is 83 ,, Example 3-1000 kg of crystalline sodium fluoride, containing 98% NaF and 2% SIOj (the weight ratio is mixed with the NaF: SiO 2613.3 kg solution of a 3% solution of aluminum fluoride, which is added aluminum sulphate to achieve a content of 0.1 (or an equivalent amount of sulfuric acid and aluminum hydroxide). The interaction process is carried out at 80-90 ° C for 0.51 h. After separating the suspension by filtration, 6 kg of a wet precipitate is obtained and 2358 , 7 kg stock solution with fluorine content of 0.6%. After drying, the precipitate contains 52.62% F, and, 08% A1, 30.1% Na, the yield of fluorine in the product is 85.9%. The expected economic effect will be 1.5 million rubles per year. Formula of the invention A method for the production of cryolite, including , a mixture of a suspension of crystalline sodium fluoride and a supersaturated solution of aluminum fluoride, characterized in that, in order to increase the yield of fluorine in the product using crystalline sodium fluoride with a weight ratio of sodium fluoride to two silica of 0.25-0.9, mixing is carried out the addition of aluminum sulphate in the amount of 0.1-1, 5 wt.%. Sources of information taken into account in the examination of 1, Guz S, Yu, Baranovsk R, G, Production of cryolite, aluminum fluoride and sodium fluoride, 2, USSR Author's Certificate 262880, class C, 01 F 7/5, 19,