US 12,404,205 B2
Method for recovering and reusing quartz powder waste in out-of-tube deposition process
Hongda Chen, Suzhou (CN); Longfei Wang, Suzhou (CN); Fan Li, Suzhou (CN); Lihong Sui, Suzhou (CN); and Yonglin Luo, Suzhou (CN)
Assigned to JIANGSU ETERN OPTICAL FIBER TECHNOLOGY CO., LTD., Suzhou (CN)
Appl. No. 17/923,927
Filed by JIANGSU ETERN OPTICAL FIBER TECHNOLOGY CO., LTD., Suzhou (CN)
PCT Filed Jul. 20, 2020, PCT No. PCT/CN2020/102937
§ 371(c)(1), (2) Date Nov. 8, 2022,
PCT Pub. No. WO2021/223325, PCT Pub. Date Nov. 11, 2021.
Claims priority of application No. 202010380533.2 (CN), filed on May 8, 2020.
Prior Publication US 2023/0167016 A1, Jun. 1, 2023
Int. Cl. C03B 37/012 (2006.01); C01B 33/12 (2006.01); C03C 13/04 (2006.01)
CPC C03C 13/046 (2013.01) [C01B 33/126 (2013.01); C03B 37/01211 (2013.01); C03B 37/01245 (2013.01); C03B 37/0126 (2013.01); C03B 2201/12 (2013.01); C03B 2201/20 (2013.01); C03C 2213/00 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A method for preparing an optical fiber preform rod having a functional quartz cladding, comprising steps of:
(S0) recovering quartz powder waste in an out-of-tube deposition process, comprising steps of
(1) acid washing: reacting a quartz powder collected in a treatment of a tail gas from deposition of an optical fiber preform rod in a hydrochloric acid solution, precipitating the quartz powder out and draining the acid solution on a surface thereof, and washing the quartz powder with pure water;
(2) separation: draining surface water from the quartz powder diluted with pure water obtained in Step (1), centrifuging, and separating the quartz powder;
(3) drying: drying the quartz powder obtained in Step (2) in a dryer lined with high-purity quartz and drying to a moisture content of 2% or less;
(4) calcinating: calcinating the quartz powder dried in Step (3) in a device lined with high-purity quartz;
(5) crushing: taking out the calcinated quartz, placing in a device lined with high-purity quartz, crushing and grinding to an average particle size of 0.2-1 mm; and
(6) pre-water removal: placing the ground quartz powder in a sealed container, and introducing a nitrogen-chlorine mixture containing 15%-25% chlorine;
(S1) assembly of optical fiber preform rod and filing filling: assembling a cladding sleeve having a cladding tail handle and a core rod having a core tail handle after Step (1) acid washing, filling a gap between the cladding sleeve and the core rod with the quartz powder prepared in step (S0) after assembly, and then filling a tail high-purity quartz column with the quartz powder;
(S2) mounting of tail cover plate: mounting a tail cover plate having a gas gauge, a gas inlet, a gas extraction port and three polytetrafluoroethylene sealing rings, to fix the core rod in place; and
(S3) hanging the optical fiber preform rod to a melt shrinkage device, doping the quartz powder, and then melt shrinking and sintering to obtain a transparent glass rod, wherein the doping gas is silicon tetrachloride or silicon tetrafluoride.