摘要：Viscosity and density are highly important physicochemical properties of copper
electrolyte since they affect the purity of cathode copper and energy consumption [1, 2]
affecting the mass and heat transfer conditions in the cell [3]. Increasing viscosity and density
decreases the rate in which the anode slime falls to the bottom of the cell [4, 5] and lowers the
diffusion coefficient of cupric ion (D Cu2+ ) [6]. Decreasing the falling rate of anode slime
increases movement of the slime to other directions than downward [4, 5]. If the anode slime
ends up on the cathode, the impurities could entrap into coating [4]. Due to that the aim is to
keep the viscosity and density sufficiently low [4]. According to the studies of Price and
Davenport [3], Subbaiah and Das [2], Devochkin et al. [7] as well as Jarjoura et al. [8]
increasing the concentration of copper, nickel and sulfuric acid increases both viscosity and
density, while temperature decreases these properties. In addition, Price and Davenport [1]
researched the effect of impurities arsenic and iron as well as Subbaiah and Das [2] the effect
of iron, manganese and cobalt. All of these researchers found that those impurities increased
both viscosity and density. The density and kinematic viscosity of copper electrorefining
electrolytes have not been extensively researched under electrorefining conditions. The
kinematic viscosity is also an important factor in the equation defining D Cu2+ using a rotating
disc electrode technique [6]. The errors in the viscosity values cause significant error to D Cu2+ .
Thus, this work introduces mathematical models for the density and kinematic viscosity. The
kinematic viscosity of the test electrolytes was measured with a Ubbelohde capillary
viscometer from Schott-Geräte GmbH and the density with a glass tube oscillator DMA 40
Digital Density Meter from Anton Paar K. G. The temperature (50, 60, 70 °C) and electrolyte
composition were used as variables. The composition variables investigated were copper (40,
50, 60 g/dm 3 ), nickel (0, 10, 20 g/dm 3 ) and sulfuric acid (130, 145, 160 g/dm 3 ) in all models,
and additionally the effect of arsenic acid for the viscosity was studied (0, 15, 30 g/dm 3 ). The
electrolytes used in these tests were prepared from CuSO 4 ∙5H 2 O (99–100 %), NiSO 4 ∙7H 2 O
(99–100 %), H 2 SO 4 (95–97 %) and arsenic acid (containing As 151700 mg/dm 3 , Bi 6.2
mg/dm 3 , Se 0.07 mg/dm 3 , Te 18.6 mg/dm 3 , Ag 0.2 mg/dm 3 , Cu 4794 mg/dm 3 , Ni 1688
mg/dm 3 , Pb 28.62 mg/dm 3 and Sb 3954 mg/dm 3 ).
