Nickel-Cobalt-Sulfide - OREAS-78 - ColdBlock Technologies

APPLICATION NOTE

Nickel-Cobalt-Sulfide – OREAS-78

SUMMARY

This application note is for the digestion of OREAS-78, a Nickel-Cobalt Sulfide.

Instrument:	ColdBlock CBM Pro Series, chiller, ICP-OES
Published:	April 2025
Digestion Time:	20 Minutes
Acid Used:	Reverse Aqua Regia
Average ColdBlock Recovery vs. CRM:	100% Nickel 98% Cobalt 94% Sulfur

METHODOLOGY

Chiller temperature was set to -5°C
0.25g of OREAS-78 was weighed and placed into a ColdBlock digestion vessel
20mL of reverse aqua regia was added (HNO₃ is added first, followed by the HCl)
Sample was digested at 80% power for 20 minutes
Sample was cooled and bulked to 50mL using 2% HNO_3v/v

DISCUSSION

Upon addition of HNO3, the evolution of reddish brown (NO2) fumes occurred
After 20 minutes, the samples were mostly clear
After bulking up, the samples turned slightly pink, and a trace amount of material settled on the bottom of the tube
Hydrofluoric acid can be added for a “near-total” digestion

OREAS 78 after digestion completed

OREAS 78 after bulk up with 2% HNO₃

OREAS 78 is a nickel-cobalt sulphide certified reference material (CRM) prepared from a nickel matte byproduct during the refining process at a nickel refinery.

Results

OREAS 78, Nickel-Cobalt Sulfide
Method:	0.25g – Add 15mL HNO₃, and 5mL HCl and digest at 70% power for 20 minutes. Let cool, and bulk to 50mL
Element	Certified Value	ColdBlock k Value 1	ColdBlock Value 2	ColdBlock Value 3	ColdBlock Value 4	ColdBlock Value 5	ColdBlock Average	Stdev	% RSD	% Recovery vs Certified
Ni (wt.%)	25.79	25.52	26.06	25.22	25.99	25.73	25.79	0.35	1.3%	100%
Co (wt.%)	23.74	22.90	23.41	22.81	23.62	23.20	23.16	0.34	1.5%	98%
S (wt.%)	28.61	26.24	27.50	27.29	27.76	27.02	26.87	0.58	2.2%	94%

Click here to download the Application Note in PDF format.

Join our monthly e-newsletter for expert tips, updates, and exclusive content delivered straight to your inbox.

ColdBlock Technologies Inc.
4551 Zimmerman Ave
Niagara Falls, ON L2E 3M5
info@coldblock.ca.