Precipitated Silica Process via Two-Phase Sodium Control
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Solution Overview
Problem
Existing processes for preparing precipitated silica are limited by inefficiencies and high costs, requiring an optimized and economical method to achieve a wide range of surface areas and pore volumes for various industrial applications.
Innovation Solution
A process involving the preparation of an aqueous sodium silicate solution at a pH of 10.6 to 10.8, with simultaneous addition of sodium silicate, water, and acid in multiple phases to control sodium ion concentration, resulting in precipitated silica with a CTAB surface area of 150 to 350 m^2/g and a BET surface area of 190 to 380 m^2/g, allowing for inverse proportionality of CTAB surface area to sodium ion concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional processes are used to prepare precipitated silica, then production can be achieved, but the processes are inefficient and costly with limited application
Solution Approach 1:
The patent applies parameter changes by precisely controlling the sodium ion concentration in two distinct phases (0.13-0.57 normal in initial phase, 0.3-0.9 normal in final phase) and maintaining specific pH ranges (10.6-10.8 for sodium silicate solution, 3-4.5 for final acidification). This systematic parameter control enables efficient production of precipitated silica with tailored surface area (150-350 m²/g CTAB) and pore volume, resolving the contradiction between manufacturing efficiency and process complexity.
2Adaptability or versatility
If a wide range of surface areas is required for different applications, then product versatility is improved, but process optimization becomes more difficult
Solution Approach 1:
The patent employs dynamics by implementing a two-phase addition process where the sodium ion concentration is dynamically adjusted between phases. The initial phase uses lower sodium ion concentration (0.13-0.57 normal) while the final phase uses higher concentration (0.3-0.9 normal), allowing precise control over the final surface area and pore volume characteristics. This dynamic adjustment enables production of silica suitable for various applications from 150-350 m²/g CTAB surface area.
Solution Approach 2:
By systematically varying the sodium ion concentration parameters between two phases and controlling pH ranges (10.6-10.8 initially, 3-4.5 finally), the process achieves precise control over surface area and pore volume, enabling versatile application while maintaining manufacturing precision.
3Ease of manufacture
If existing manufacturing setups are maintained, then cost-effectiveness is improved, but process optimization opportunities are limited
Solution Approach 1:
The patent applies self-service by utilizing standard manufacturing equipment and conventional reagents (sodium silicate and acid) that are already available in existing setups. The process requires no specialized or expensive equipment, allowing industries to implement the optimized process using their current infrastructure, thereby achieving cost-effectiveness while improving manufacturing efficiency through better parameter control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This process efficiently produces precipitated silica with a controlled surface area and pore volume, suitable for use in rubber and elastomer compositions, enhancing the manufacturing efficiency and cost-effectiveness by maintaining existing manufacturing setups.
Implementation Method 1
water glass is reacted with sulphuric acid
Implementation Method 2
obtain precipitated silica
Implementation Method 3
the adsorption of nitrogen commonly referred to as BET (after Brunauer, Emmett and Teller) surface area
Implementation Method 4
the adsorption of Cetyl trimethyl ammonium bromide (CTAB) on the surface of silica
Data Source
Figure 1~2
AI summary
A process for preparing precipitated silica, is disclosed. The process includes preparing an aqueous solution of sodium silicate having a pH in a range of 10.6 to 10.8, simultaneously adding to said aqueous solution of sodium silicate, a sodium silicate solution, water and an acid in at least two phases to obtain a reaction mixture, wherein in an initial phase the sodium silicate solution, the water and the acid is added till the sodium ion concentration of the reaction mixture is in range of 0.13 normal to 0.57 normal and in a final phase the sodium silicate solution, the water and the acid is added till the sodium ion concentration of the reaction mixture is in a range of 0.3 to 0.9 normal; acidifying the reaction mixture with the acid to a pH in a range of 3 to 4.5, aging the reaction mixture to obtain precipitated silica and recovering the precipitated silica from the reaction mixture.