Before working with this product, you must read and become familiar with the available information on its risks, proper use, and handling. Information is available in several forms, e.g., in particular in the currently valid safety data sheets and product labels. For further information contact your Covestro representative.
Product description
Caustic soda 50% is a solution of sodium hydroxide (NaOH) in water and is commercially available in the following grade:
Name: Caustic soda 50%
Percent by weight: 49 – 51 %
Caustic soda 50% is supplied in rail tankers, road tankers or ships, and by pipeline from the Leverkusen, Dormagen and Tarragona Chemparks.
Applications
Technical chemistry: Production of soaps and detergents, dyestuffs, sodium compounds, regeneration of ion exchange resins
Aluminum industry: Production of fused alumina by bauxite pulping
Pulp and paper industry: Soda cellulose and sulfate cellulose production
Textile Industry: Production of viscose silk (synthetic wool)
Electrical Vehicles: LiOH production, cathode active materials production
Various: Neutralization, alkalization, degreasing, pickling of metal surfaces
Specification
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Caustic Soda (NaOH) | 49 - 51 | % | 2042-0400401-16D | |
| Chloride | 60 | mg/kg | 2042-0404001-16D | |
| Sulfate | 40 | mg/kg | 2011-0572501-99D | |
| Carbonate | 150 | mg/kg | AC-F 1249 | |
| Chlorate | 15 | mg/kg | 2011-0572501-99D | |
| Silica (as SiO2) | 10 | mg/kg | 2042-0411701-16D | |
| Iron (as Fe2+ a. Fe3+) | 5 | mg/kg | 2042-0411701-16D | |
| Aluminium | 1 | mg/kg | 2042-0411701-16D | |
| Alkaline Earths (as Ca^2+) | 5 | mg/kg | 2042-0411701-16D | |
| Mercury | 0,01 | mg/kg | 2042-0402501-16D | |
| Nickel | 1 | mg/kg | 2042-0411701-16D |
Typical Values
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| State of matter | 20 °C | liquid | ||
| Density | 15 °C | 1.54 | g/cm³ | DIN 51757 |
| Density | 20 °C | 1.52 | g/cm³ | DIN 51757 |
| Density | 50 °C | 1.505 | g/cm³ | DIN 51757 |
| Boiling point | 1,013 hPa | 143.00 | °C | |
| Melting point | 12.00 | °C | ||
| Melting point | 12.00 | °C | ||
| pH-value | 20 °C | > 14.00 | ||
| pH-value | 14.00 | |||
| Viscosity, dynamic | 20 °C | 85 | mPa·s | |
| Color | colourless | |||
| Odor | odourless | |||
| Odor | Odorless |
Caustic soda solution is a strongly alkaline, caustic, water-clear, odorless liquid which is infinitely miscible with water.
When open to the air, it becomes cloudy due to absorption of carbon dioxide with formation of sodium carbonate.
| NaOH % | Density g/l (20°C) | Boiling Point °C | Solidification °C |
|---|---|---|---|
| 10 | 1.109 | 103 | -10 |
| 20 | 1.219 | 108 | -34 |
| 30 | 1.328 | 116 | +1 |
| 32 | 1.349 | 120 | +7 |
| 33 | 1.359 | 119 | +8 |
| 40 | 1.430 | 128 | +15 |
| 45 | 1.478 | 135 | +7 |
| 50 | 1.525 | 143 | +12 |
It should be noted that 50 % caustic soda solution already becomes viscous at about 15 °C and can only be pumped with difficulty.
The average values of the dynamic viscosities (mPa*s) of 10 to 50 % caustic soda solution at temperatures of 20 - 80 °C are shown in the following table:
| NaOH (%) | 20 °C | 40 °C | 60 °C | 80 °C |
|---|---|---|---|---|
| 10 | 1.9 | 1.2 | 0.83 | 0.65 |
| 20 | 4.2 | 2.3 | 1.5 | 1.0 |
| 30 | 13 | 6.0 | 3.1 | 1.9 |
| 32 | 17 | 7.0 | 3.7 | 2.2 |
| 33 | 18 | 7.5 | 3.8 | 2.3 |
| 40 | 37 | 12.0 | 6.1 | 3.4 |
| 45 | 56 | 17.0 | 7.8 | 4.4 |
| 50 | 85 | 23.0 | 9.7 |
5.4 |
Health and Safety Information
Disclaimer
General
The manner in which you use our products, technical assistance and information (whether verbal, written or by way of production evaluations), including any suggested formulations and recommendations, are beyond our control. Therefore, it is imperative that you test our products to determine suitability for your processing and intended uses. Your analysis must at least include testing to determine suitability from a technical, health, safety, and environmental and regulatory standpoint. Such testing has not necessarily been done by Covestro, and Covestro has not obtained any approvals or licenses for a particular use or application of the product.
Unless we otherwise agree in writing, all products are sold strictly pursuant to the terms of our standard conditions of sale which are available upon request.
All information and including technical assistance is given without warranty or guarantee and is subject to change without notice. It is expressly understood and agreed by you that you assume and hereby expressly release indemnify us and hold us harmless from all liability, in tort, contract or otherwise, incurred in connection with the use of our products, technical assistance, and information. Any statement or recommendation not contained herein is unauthorized and shall not bind us. Nothing herein shall be construed as a recommendation to use any product in conflict with any claim of any patent relative to any material or its use. No license is implied or in fact granted under the claims of any patent.
Non Medical and non Food Contact
This product is not designated for the manufacture of a medical device or of intermediate products for medical devices (1). This product is also not designated for other specifically regulated applications (e.g. including cosmetics, plant protection, fertilisers, plant strengtheners, food processing, food contact and others). If the intended use of the product is for the manufacture of a medical device or of intermediate products for medical devices or for other specifically regulated applications Covestro must be contacted in advance to provide its agreement to sell such product for such purpose. Nonetheless, any determination as to whether a product is appropriate for use in a medical device or intermediate products for medical devices, for Food Contact products or cosmetic applications must be made solely by the purchaser of the product without relying upon any representations by Covestro.
1) Please see the Guidance on Use of Covestro Products in a Medical Application document.
Sample
Any samples provided by Covestro are for testing purposes only and not for commercial use.
Typical value
These values are typical values only. Unless explicitly agreed in written form, they do not constitute a binding material specification or warranted values
Contact
Please use our contact form or contact us directly by sending an e-mail to technical-datasheets@cx.covestro.com .
