Banca de DEFESA: JULIANA ABREU DE FREITAS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JULIANA ABREU DE FREITAS
DATE: 23/05/2023
TIME: 14:00
LOCAL: meet.google.com/syk-qutf-yec
TITLE:

Evaluation of cyanide removal processes  from water effluents from gold ore processing  and industrial scaling

KEY WORDS:

cyanide; oxidation; effluent treatment; Fenton process; activated carbon.

PAGES: 47
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
SPECIALTY: Processos Inorgânicos
SUMMARY:

Gold ore extraction process goes through different steps, from mineral research to physicalchemical processing steps, which use chemical reagents for extraction, such as cyanide. This
work aims to evaluate the removal of cyanide in the effluent generated after the gold ore
beneficiation process, seeking to integrate the conceptual part of the literature with bench tests
and industrial application, with optimization of results. Chemical treatment routes were studied
by oxidation using hydrogen peroxide and the Fenton process and by adsorption on activated
carbon in batches in a Jar Test apparatus. The oxidation processes were then scaled up to an
industrial scale. It was proven that these processes are capable of removing cyanide at the levels
required for recirculation of the effluent in the process, 1,0 mg/L of free cyanide and 30,0 mg/L
of total cyanide, reaching removal of 89% (± 2) of free cyanide and 90 % (± 3) of total cyanide.
A statistical study was then carried out using a DOE tool to evaluate the interaction between
the dosages of hydrogen peroxide and ferrous chloride at different pH values, in order to
optimize the dosage to reduce the operational costs of this decontamination process. The results
indicated that it is possible to remove cyanide in sufficient quantity to reuse the effluent (higher
than 96% of removal), using 88% less hydrogen peroxide and 70% less ferrous chloride,
working at pH 3, resulting in lower operating expenses for effluent treatment.

BANKING MEMBERS:
Presidente - 1759475 - JORGE DAVID ALGUIAR BELLIDO
Interno - 1532720 - JACKSON DE OLIVEIRA PEREIRA
Interno - 1893854 - ALEXANDRE BOSCARO FRANCA
Externa à Instituição - JOSY ANTEVELI OSAJIMA FURTINI - UFPI