19th International CODATA Conference
Category: Knowledge Discovery

Creating Experimental Data of Geo-chemical Kinetics and Data Base

Ronghua Zhang (zrhhsm@bj163.com, zrhhsm@pku.edu.cn), Xuetong Zhang, Shumin Hu
Open Research Lab. of Geochemical Kinetics, Chinese Academy of Geological Sciences, China

Junsheng Zhang, Yan Fang, Rongfang Bie
College of Information Science, Beijing Normal University, China

Data of reaction rates of minerals and rocks in waters at high temperatures T and high pressures P were obtained in experimental laboratories and have been accumulated in the last 20 years. Those data are important in understanding the water-rock interactions in lithosphere, and in dealing with the pollution of ground water and deep buried nuclear wastes. Most reaction rates have been measured experimentally in the T range 25 to 400°C and at various pressures. Global world and our lab measured a lot of mineral dissolution rates (or precipitation rates) in aqueous solutions at high T and P. The experimental data include mineral (silicate (feldspar, pyroxene, amphibolites…) carbonate, metal-oxides,) dissolution rates (or precipitation rates), in various solutions and rates of rock-water interactions, which were measured using different reactors. 

The kinetics data system is constructed to an analog for water – rock (mineral material) interactions in nature. It is convenient for users to apply it to resolve problems in theoretical analyses and in field observation.

The logic structure of the kinetic data base consists of several subsystems: 1) mineral (rock) subsystem: mineral characters, compositions, structure, occurrence, surface nature (surface area), …2) fluid subsystem: water and aqueous solution, compositions and treatment methods…3) reaction subsystem: hydrodynamic (flow rate) and t (contact time, accumulation time), reactor type (Continuous stirred tank reactor, Plug flow reactor, Packed bed reactor, Disc, Batch,); open system/closed system; initial state of the experimental system, operation methods; 4) reaction condition: physicochemical conditions; 5) reaction results: it includes rate law, rate constant k, activation energy E_a, entropy, enthalpy, chemical affinity A, Gibbs free energy, etc.), surface modification, steady state and non-steady state kinetics, distance to equilibrium state, non-linear kinetics, …6) analytical methods and reactor equipments.7) calculation: kinetics and dynamics.8) reference subsystem. 9) Graph subsystem.

Rules to predict kinetics data system can be classified: one is described by definitely theory based on experiment results, e.g. rate law equations; the other is described by probability and statistic theory based on system oneness, such as rate order calculation. With the theoretical and imperial rules, we can predict the unknown kinetics data according to the data in existence. Based on normalization theory, in order to enable the database structure to be 3NF, and reduce the query connection amount to get better performance, we allow some data redundancy to exist and to do some denormalization operation. The designing enables data of different formats to enter the kinetic database with uniform and unified parameter nomination.

*Supported by the Ministry of Science and technology Project of ‘CODATA Chinese data base for physics and chemistry’.