CS262074B1

CS262074B1 - Process for preparing pure potash water glasses from sodium water glass

Info

Publication number: CS262074B1
Application number: CS873036A
Authority: CS
Inventors: Miloslav Ing Novotny; Jiri Dolezal
Original assignee: Novotny Miloslav; Jiri Dolezal
Priority date: 1987-04-29
Filing date: 1987-04-29
Publication date: 1989-02-10
Also published as: CS303687A1

Abstract

Zředěné vodní sklo se podrobí dealkaliz-ací na katexu v H+ cyklu a získaný kyselý roztok SiO2 se po přídavku malého množství · vodního skla nebo hydroxidu zahustí na SIO2 20 až 50 °/o. Zahuštěný roztok se nechá zreagovat s hydroxidem draselným na draselné vodní sklo.The dilute water glass is dealt with on the cation exchanger in the H + cycle and recovered acidic SiO 2 solution is added after addition of a small amount Water glass or hydroxide is concentrated at SIO2 20 to 50 ° / o. Concentrate the solution treated with potassium hydroxide to potassium water glass.

Description

Vynález se týká způsobu výroby čistých draselných vodních skel ze sodného vodního skla.The invention relates to a process for the production of pure potassium water glasses from sodium water glass.

Doposud známé postupy výroby draselného vodního skla vycházejí z pevného kremičitanu draselného. Po jeho rozvaření parou za vyšší teploty a tlaku v autoklávu vznikne draselné vodní sklo tekuté. Jiný způsob je znám podle dánského patentu 2 619 604, kde je popsána výroba draselných a sodných vodních skel rozpouštěním amorfního kysličníku křemičitého v roztoku alkalického hydroxidu za atmosférického tlaku a teploty pod 100 °C. Podle patentu NDR 113 515 je znám způsob výroby draselného vodního skla, jehož princip spočívá v tom, že se roztok koloidního kysličníku křemičitého deionizuje nejdříve pomocí katexu v H⁺ formě a následně pomocí anexu v OH^- formě. Deionizovaný roztok se nechá zreagovat s roztokem hydroxidu draselného při teplotě 98 °G. Jiný způsob vychází z roztoku koloidního kysličníku křemičitého, který je zahřát na teplotu 75 až 102 °C a při této teplotě se nechá zreagovat s 24- až 65% roztokem hydroxidu draselného na draselné vodní sklo.The prior art processes for producing potassium water glass are based on solid potassium silicate. After boiling with steam at higher temperature and pressure in the autoclave, the potassium water glass is liquid. Another method is known according to Danish patent 2,619,604, which describes the production of potassium and sodium water glasses by dissolving amorphous silica in an alkali hydroxide solution at atmospheric pressure and a temperature below 100 ° C. According DDR Patent 113 515 discloses a process for producing potassium water glass, whose principle consists in that a solution of colloidal silica first with deionized ion exchanger in H ⁺ form, followed by anion exchange resin in OH ^- form. The deionized solution was reacted with a potassium hydroxide solution at 98 ° C. Another method starts from a solution of colloidal silica which is heated to a temperature of 75-102 ° C and is reacted at this temperature with a 24-65% potassium hydroxide solution to a potassium water glass.

Výhodnějším se jeví způsob výroby draselných vodních skel podle vynálezu, jehož podstata spočívá v tom, že se sodné vodní sklo zředí destilovanou nebo deionizovanou vodou na koncentraci 2 — 6 % S1O2 a podrobí se dealkalizaci průchodem přes katex v H⁺ cyklu. Tímto způsobem se připraví kyselý roztok kysličníku křemičitého mající pH 2 — 5. K části kyselého roztoku kysličníku křemičitého se přidá stabilizační přísada draselného nebo sodného vodního skla případně roztoku hydroxidu draselného tak, aby pH bylo upraveno na hodnotu 9 — 12 a poté se začne se zahušťováním. Je prováděno v zahušťováku odpařováním vody za přívodu tepla, přičemž odpařená voda je doplňována zředěným kyselým roztokem kysličníku křemičitého. Zahušťování je ukončeno dosažením koncentrace S1O2 20 až 50 %. Zahuštěný roztok se nechá zreagovat s pevným hydroxidem draselným nebo s jeho vodným roztokem v takovém poměru, aby na 1 mol kysličníku draselného, kterýThe process according to the invention appears to be more advantageous in that the sodium water glass is diluted with distilled or deionized water to a concentration of 2 - 6% SiO2 and subjected to dealkalization by passing through a cation exchanger in an H ⁺ cycle. In this way, an acidic silica solution having a pH of 2-5 is prepared. To a portion of the acidic silica solution, a potassium or sodium water glass stabilizer or potassium hydroxide solution is added to adjust the pH to 9-12, and then concentration begins. . It is carried out in a thickener by evaporating water under heat supply, the evaporated water being replenished with a dilute acidic silica solution. Concentration is terminated by reaching a concentration of S1O2 of 20 to 50%. The concentrated solution is reacted with the solid potassium hydroxide or with its aqueous solution in a ratio such that per mole of potassium oxide,

Claims

Subject

Process for producing pure potassium water glasses from sodium water glass, characterized in that the sodium water glass is diluted with distilled or deionized water to a concentration of S1O2 of 2-5% and subjected to dealkalization by passing through a cation exchanger in H ⁺ form to prepare an acidic oxide solution. To a portion of the acidic silica solution, a stabilizing additive of potassium or sodium water glass or a solution of potassium hydroxide is added, so that the pH contained in the potassium hydroxide used is 2-4 moles of the silica contained in the concentrated solution.

In this way, virtually any pure potassium water glass can be prepared.

The process according to the invention is also apparent from the following exemplary embodiment.

Example

Sodium liquid glass 1,834 go composition: S1O2 27%, Na2O 8.16%, H2O 64.84% was diluted 9 680 g of distilled water. In this way, 11514 g of diluted water glass having a composition of SiO2 of 4.3%, Na2O of 1.3%; the rest to one hundred percent is water. The entire amount of diluted water glass was subjected to deionization on a cation exchange column packed with Ostion KS cation exchanger in H + form. Dealkalization yielded 9,967 g of an acidic silica solution having a concentration of 4% SiO2 and a pH of 2.7. The remaining 1,547 g of diluted waterglass were losses due to the operation of the ion exchanger. To 967 g of an acidic silica solution having a SiO2 concentration of 4% and a pH of 2.7, 33 g of sodium water glass having a composition of SiO2 of 27%, Na2O 8.16%, H2O of 64.84% was added to prepare 1 000 g stock solution having a pH of 10.4. The stock solution was heated in a 2,000 mL glass flask equipped with a glass condenser to 102 ° C. The evaporated water was condensed in a water-cooled condenser and the decreasing volume of liquid was continuously replenished with an acidic silica solution. A total of 9,000 g of water was evaporated and 9,000 grams of an acidic silica solution with a concentration of 4% SiO2 and a pH of 2.7 was dosed. 1000 g of a concentrated SiO2 solution of 40.759%, Na2O 0.269% were obtained. To this amount, 619 g of a 46% KOH solution containing 32.22% K 2 O was added while hot and stirring. The product was then cooled. This resulted in 1,619 g of potassium water glass having the following composition: S1O2 25.17%, K2O 12.32%, Na2O 0.16%, Fe ³⁺ 0.0038% and specific gravity of 1360 kg / m ³ .

adjusted to a pH of 9-12, and then concentrated under heat supply, the evaporated water being replenished with an acidic silica solution until a S1O2 concentration of 20-50% is achieved, and the concentrated solution is reacted with solid potassium hydroxide or its aqueous solution solution in a ratio such that 2 to 4 moles of silica in the concentrated solution are present per mole of potassium oxide contained in the potassium hydroxide used.