Linear growth rates of single copper sulfate crystals

Author

Arthur Oswald Hansen, New Jersey Institute of Technology

Document Type

Thesis

Date of Award

6-30-1954

Degree Name

Master of Science in Chemical Engineering - (M.S.)

Department

Chemical Engineering

First Advisor

George C. Keeffe

Second Advisor

C. L. Mantell

Abstract

The purpose of this work was to study and measure the factors influencing crystal growth.

Approximately 250 single crystals of CuSO₄.5H₂O were grown under controlled conditions of supersaturation, solution velocity, and temperature.

The data from this work indicates that:

(a) Crystal growth rate is independent of crystal size for the size range covered (4 to 12 mesh).

(b) Crystal growth rate is directly proportional to the degree of supersaturation, or driving force for each concentration of solution studied.

(c) Crystal growth rate varies exponentially with the velocity of the solution passing the crystal
R_D = f(u^m)

(d) The value of the exponent "m" increases as the temp-erature (and concentration) of the growth solution increases. This indicates that there must be more than one dimensionless group containing the velocity term.

The following empirical equations were obtained for the four different solutions used:

Solution A - Saturation temperature = 28° C.
Log R_D/ΔC = 0.240 Log u + 0.2900

Solution B - Saturation temperature = 37° C.
Log R_D/ΔC = 0.265 Log u + 0.5682

Solution C - Saturation temperature = 47° C.
Log R_D/ΔC = 0.288 Log u + 0.6128

Solution D - Saturation temperature = 58° C.
Log R_D/ΔC = 0.407 Log u + 0.6721

(e) The following empirical equation was derived which composites the above equations and which effectively summarizes all the data in this work:
R_D = 30,000 ΔCu²e (-2950u^.143/τ)

The velocity range in this work was from 2.2 to 20.6 centimeters per second.

Recommended Citation

Hansen, Arthur Oswald, "Linear growth rates of single copper sulfate crystals" (1954). Theses. 2256.
https://digitalcommons.njit.edu/theses/2256